1VI(1P) POSIX Programmer's Manual VI(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 vi — screen-oriented (visual) display editor
13
15 vi [-rR] [-c command] [-t tagstring] [-w size] [file...]
16
18 This utility shall be provided on systems that both support the User
19 Portability Utilities option and define the POSIX2_CHAR_TERM symbol.
20 On other systems it is optional.
21 The vi (visual) utility is a screen-oriented text editor. Only the open
23 and visual modes of the editor are described in POSIX.1‐2008; see the
24 line editor ex for additional editing capabilities used in vi. The
25 user can switch back and forth between vi and ex and execute ex com‐
26 mands from within vi.
27 This reference page uses the term edit buffer to describe the current
29 working text. No specific implementation is implied by this term. All
30 editing changes are performed on the edit buffer, and no changes to it
31 shall affect any file until an editor command writes the file.
32 When using vi, the terminal screen acts as a window into the editing
34 buffer. Changes made to the editing buffer shall be reflected in the
35 screen display; the position of the cursor on the screen shall indicate
36 the position within the editing buffer.
37 Certain terminals do not have all the capabilities necessary to support
39 the complete vi definition. When these commands cannot be supported on
40 such terminals, this condition shall not produce an error message such
41 as ``not an editor command'' or report a syntax error. The implementa‐
42 tion may either accept the commands and produce results on the screen
43 that are the result of an unsuccessful attempt to meet the requirements
44 of this volume of POSIX.1‐2017 or report an error describing the termi‐
45 nal-related deficiency.
46
48 The vi utility shall conform to the Base Definitions volume of
49 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines, except that '+'
50 may be recognized as an option delimiter as well as '-'.
51 The following options shall be supported:
53 -c command
55 See the ex command description of the -c option.
56 -r See the ex command description of the -r option.
58 -R See the ex command description of the -R option.
60 -t tagstring
62 See the ex command description of the -t option.
63 -w size See the ex command description of the -w option.
65
67 See the OPERANDS section of the ex command for a description of the op‐
68 erands supported by the vi command.
69
71 If standard input is not a terminal device, the results are undefined.
72 The standard input consists of a series of commands and input text, as
73 described in the EXTENDED DESCRIPTION section.
74 If a read from the standard input returns an error, or if the editor
76 detects an end-of-file condition from the standard input, it shall be
77 equivalent to a SIGHUP asynchronous event.
78
80 See the INPUT FILES section of the ex command for a description of the
81 input files supported by the vi command.
82
84 See the ENVIRONMENT VARIABLES section of the ex command for the envi‐
85 ronment variables that affect the execution of the vi command.
86
88 See the ASYNCHRONOUS EVENTS section of the ex for the asynchronous
89 events that affect the execution of the vi command.
90
92 If standard output is not a terminal device, undefined results occur.
93 Standard output may be used for writing prompts to the user, for infor‐
95 mational messages, and for writing lines from the file.
96
98 If standard output is not a terminal device, undefined results occur.
99 The standard error shall be used only for diagnostic messages.
101
103 See the OUTPUT FILES section of the ex command for a description of the
104 output files supported by the vi command.
105
107 If the terminal does not have the capabilities necessary to support an
108 unspecified portion of the vi definition, implementations shall start
109 initially in ex mode or open mode. Otherwise, after initialization, vi
110 shall be in command mode; text input mode can be entered by one of sev‐
111 eral commands used to insert or change text. In text input mode, <ESC>
112 can be used to return to command mode; other uses of <ESC> are
113 described later in this section; see Terminate Command or Input Mode.
114 Initialization in ex and vi
116 See Initialization in ex and vi for a description of ex and vi initial‐
117 ization for the vi utility.
118 Command Descriptions in vi
120 The following symbols are used in this reference page to represent
121 arguments to commands.
122 buffer See the description of buffer in the EXTENDED DESCRIPTION sec‐
124 tion of the ex utility; see Command Descriptions in ex.
125 In open and visual mode, when a command synopsis shows both
127 [buffer] and [count] preceding the command name, they can be
128 specified in either order.
129 count A positive integer used as an optional argument to most com‐
131 mands, either to give a repeat count or as a size. This argu‐
132 ment is optional and shall default to 1 unless otherwise speci‐
133 fied.
134 The Synopsis lines for the vi commands <control>‐G, <con‐
136 trol>‐L, <control>‐R, <control>‐], %, &, ^, D, m, M, Q, u, U,
137 and ZZ do not have count as an optional argument. Regardless,
138 it shall not be an error to specify a count to these commands,
139 and any specified count shall be ignored.
140 motion An optional trailing argument used by the !, <, >, c, d, and y
142 commands, which is used to indicate the region of text that
143 shall be affected by the command. The motion can be either one
144 of the command characters repeated or one of several other vi
145 commands (listed in the following table). Each of the applica‐
146 ble commands specifies the region of text matched by repeating
147 the command; each command that can be used as a motion command
148 specifies the region of text it affects.
149 Commands that take motion arguments operate on either lines or
151 characters, depending on the circumstances. When operating on
152 lines, all lines that fall partially or wholly within the text
153 region specified for the command shall be affected. When oper‐
154 ating on characters, only the exact characters in the specified
155 text region shall be affected. Each motion command specifies
156 this individually.
157 When commands that may be motion commands are not used as
159 motion commands, they shall set the current position to the
160 current line and column as specified.
161 The following commands shall be valid cursor motion commands:
163 <apostrophe> ( - j H
166 <carriage-return> ) $ k L
167 <comma> [[ % l M
168 <control>-H ]] _ n N
169 <control>-N { ; t T
170 <control>-P } ? w W
171 <grave-accent> ^ b B
172 <newline> + e E
173 <space> | f F
174 <zero> / h G
175 Any count that is specified to a command that has an associated
177 motion command shall be applied to the motion command. If a
178 count is applied to both the command and its associated motion
179 command, the effect shall be multiplicative.
180 The following symbols are used in this section to specify locations in
182 the edit buffer:
183 current character
185 The character that is currently indicated by the cursor.
186 end of a line
188 The point located between the last non-<newline> (if any) and
189 the terminating <newline> of a line. For an empty line, this
190 location coincides with the beginning of the line.
191 end of the edit buffer
193 The location corresponding to the end of the last line in the
194 edit buffer.
195 The following symbols are used in this section to specify command
197 actions:
198 bigword In the POSIX locale, vi shall recognize four kinds of bigwords:
200 1. A maximal sequence of non-<blank> characters preceded and
202 followed by <blank> characters or the beginning or end of a
203 line or the edit buffer
204 2. One or more sequential blank lines
206 3. The first character in the edit buffer
208 4. The last non-<newline> in the edit buffer
210 word In the POSIX locale, vi shall recognize five kinds of words:
212 1. A maximal sequence of letters, digits, and underscores,
214 delimited at both ends by:
215 -- Characters other than letters, digits, or underscores
217 -- The beginning or end of a line
219 -- The beginning or end of the edit buffer
221 2. A maximal sequence of characters other than letters, dig‐
223 its, underscores, or <blank> characters, delimited at both
224 ends by:
225 -- A letter, digit, underscore
227 -- <blank> characters
229 -- The beginning or end of a line
231 -- The beginning or end of the edit buffer
233 3. One or more sequential blank lines
235 4. The first character in the edit buffer
237 5. The last non-<newline> in the edit buffer
239 section boundary
241 A section boundary is one of the following:
242 1. A line whose first character is a <form-feed>
244 2. A line whose first character is an open curly brace ('{')
246 3. A line whose first character is a <period> and whose second
248 and third characters match a two-character pair in the sec‐
249 tions edit option (see ex)
250 4. A line whose first character is a <period> and whose only
252 other character matches the first character of a two-char‐
253 acter pair in the sections edit option, where the second
254 character of the two-character pair is a <space>
255 5. The first line of the edit buffer
257 6. The last line of the edit buffer if the last line of the
259 edit buffer is empty or if it is a ]] or } command; other‐
260 wise, the last non-<newline> of the last line of the edit
261 buffer
262 paragraph boundary
264 A paragraph boundary is one of the following:
265 1. A section boundary
267 2. A line whose first character is a <period> and whose second
269 and third characters match a two-character pair in the
270 paragraphs edit option (see ex)
271 3. A line whose first character is a <period> and whose only
273 other character matches the first character of a two-char‐
274 acter pair in the paragraphs edit option, where the second
275 character of the two-character pair is a <space>
276 4. One or more sequential blank lines
278 remembered search direction
280 See the description of remembered search direction in ex.
281 sentence boundary
283 A sentence boundary is one of the following:
284 1. A paragraph boundary
286 2. The first non-<blank> that occurs after a paragraph bound‐
288 ary
289 3. The first non-<blank> that occurs after a <period> ('.'),
291 <exclamation-mark> ('!'), or <question-mark> ('?'), fol‐
292 lowed by two <space> characters or the end of a line; any
293 number of closing parenthesis (')'), closing brackets
294 (']'), double-quote ('"'), or single-quote (<apostrophe>)
295 characters can appear between the punctuation mark and the
296 two <space> characters or end-of-line
297 In the remainder of the description of the vi utility, the term ``buf‐
299 fer line'' refers to a line in the edit buffer and the term ``display
300 line'' refers to the line or lines on the display screen used to dis‐
301 play one buffer line. The term ``current line'' refers to a specific
302 ``buffer line''.
303 If there are display lines on the screen for which there are no corre‐
305 sponding buffer lines because they correspond to lines that would be
306 after the end of the file, they shall be displayed as a single <tilde>
307 ('~') character, plus the terminating <newline>.
308 The last line of the screen shall be used to report errors or display
310 informational messages. It shall also be used to display the input for
311 ``line-oriented commands'' (/, ?, :, and !). When a line-oriented com‐
312 mand is executed, the editor shall enter text input mode on the last
313 line on the screen, using the respective command characters as prompt
314 characters. (In the case of the ! command, the associated motion shall
315 be entered by the user before the editor enters text input mode.) The
316 line entered by the user shall be terminated by a <newline>, a
317 non-<control>‐V-escaped <carriage-return>, or unescaped <ESC>. It is
318 unspecified if more characters than require a display width minus one
319 column number of screen columns can be entered.
320 If any command is executed that overwrites a portion of the screen
322 other than the last line of the screen (for example, the ex suspend or
323 ! commands), other than the ex shell command, the user shall be
324 prompted for a character before the screen is refreshed and the edit
325 session continued.
326 <tab> characters shall take up the number of columns on the screen set
328 by the tabstop edit option (see ex), unless there are less than that
329 number of columns before the display margin that will cause the dis‐
330 played line to be folded; in this case, they shall only take up the
331 number of columns up to that boundary.
332 The cursor shall be placed on the current line and relative to the cur‐
334 rent column as specified by each command described in the following
335 sections.
336 In open mode, if the current line is not already displayed, then it
338 shall be displayed.
339 In visual mode, if the current line is not displayed, then the lines
341 that are displayed shall be expanded, scrolled, or redrawn to cause an
342 unspecified portion of the current line to be displayed. If the screen
343 is redrawn, no more than the number of display lines specified by the
344 value of the window edit option shall be displayed (unless the current
345 line cannot be completely displayed in the number of display lines
346 specified by the window edit option) and the current line shall be
347 positioned as close to the center of the displayed lines as possible
348 (within the constraints imposed by the distance of the line from the
349 beginning or end of the edit buffer). If the current line is before the
350 first line in the display and the screen is scrolled, an unspecified
351 portion of the current line shall be placed on the first line of the
352 display. If the current line is after the last line in the display and
353 the screen is scrolled, an unspecified portion of the current line
354 shall be placed on the last line of the display.
355 In visual mode, if a line from the edit buffer (other than the current
357 line) does not entirely fit into the lines at the bottom of the display
358 that are available for its presentation, the editor may choose not to
359 display any portion of the line. The lines of the display that do not
360 contain text from the edit buffer for this reason shall each consist of
361 a single '@' character.
362 In visual mode, the editor may choose for unspecified reasons to not
364 update lines in the display to correspond to the underlying edit buffer
365 text. The lines of the display that do not correctly correspond to text
366 from the edit buffer for this reason shall consist of a single '@'
367 character (plus the terminating <newline>), and the <control>‐R command
368 shall cause the editor to update the screen to correctly represent the
369 edit buffer.
370 Open and visual mode commands that set the current column set it to a
372 column position in the display, and not a character position in the
373 line. In this case, however, the column position in the display shall
374 be calculated for an infinite width display; for example, the column
375 related to a character that is part of a line that has been folded onto
376 additional screen lines will be offset from the display line column
377 where the buffer line begins, not from the beginning of a particular
378 display line.
379 The display cursor column in the display is based on the value of the
381 current column, as follows, with each rule applied in turn:
382 1. If the current column is after the last display line column used by
384 the displayed line, the display cursor column shall be set to the
385 last display line column occupied by the last non-<newline> in the
386 current line; otherwise, the display cursor column shall be set to
387 the current column.
388 2. If the character of which some portion is displayed in the display
390 line column specified by the display cursor column requires more
391 than a single display line column:
392 a. If in text input mode, the display cursor column shall be
394 adjusted to the first display line column in which any portion
395 of that character is displayed.
396 b. Otherwise, the display cursor column shall be adjusted to the
398 last display line column in which any portion of that character
399 is displayed.
400 The current column shall not be changed by these adjustments to the
402 display cursor column.
403 If an error occurs during the parsing or execution of a vi command:
405 * The terminal shall be alerted. Execution of the vi command shall
407 stop, and the cursor (for example, the current line and column)
408 shall not be further modified.
409 * Unless otherwise specified by the following command sections, it is
411 unspecified whether an informational message shall be displayed.
412 * Any partially entered vi command shall be discarded.
414 * If the vi command resulted from a map expansion, all characters
416 from that map expansion shall be discarded, except as otherwise
417 specified by the map command (see ex).
418 * If the vi command resulted from the execution of a buffer, no fur‐
420 ther commands caused by the execution of the buffer shall be exe‐
421 cuted.
422 Page Backwards
424 Synopsis:
425 [count] <control>-B
427 If in open mode, the <control>‐B command shall behave identically to
429 the z command. Otherwise, if the current line is the first line of the
430 edit buffer, it shall be an error.
431 If the window edit option is less than 3, display a screen where the
433 last line of the display shall be some portion of:
434 (current first line) -1
437 otherwise, display a screen where the first line of the display shall
439 be some portion of:
440 (current first line) - count x ((window edit option) -2)
443 If this calculation would result in a line that is before the first
445 line of the edit buffer, the first line of the display shall display
446 some portion of the first line of the edit buffer.
447 Current line: If no lines from the previous display remain on the
449 screen, set to the last line of the display; otherwise, set to (line -
450 the number of new lines displayed on this screen).
451 Current column: Set to non-<blank>.
453 Scroll Forward
455 Synopsis:
456 [count] <control>-D
458 If the current line is the last line of the edit buffer, it shall be an
460 error.
461 If no count is specified, count shall default to the count associated
463 with the previous <control>‐D or <control>‐U command. If there was no
464 previous <control>‐D or <control>‐U command, count shall default to the
465 value of the scroll edit option.
466 If in open mode, write lines starting with the line after the current
468 line, until count lines or the last line of the file have been written.
469 Current line: If the current line + count is past the last line of the
471 edit buffer, set to the last line of the edit buffer; otherwise, set to
472 the current line + count.
473 Current column: Set to non-<blank>.
475 Scroll Forward by Line
477 Synopsis:
478 [count] <control>-E
480 Display the line count lines after the last line currently displayed.
482 If the last line of the edit buffer is displayed, it shall be an error.
484 If there is no line count lines after the last line currently dis‐
485 played, the last line of the display shall display some portion of the
486 last line of the edit buffer.
487 Current line: Unchanged if the previous current character is displayed;
489 otherwise, set to the first line displayed.
490 Current column: Unchanged.
492 Page Forward
494 Synopsis:
495 [count] <control>-F
497 If in open mode, the <control>‐F command shall behave identically to
499 the z command. Otherwise, if the current line is the last line of the
500 edit buffer, it shall be an error.
501 If the window edit option is less than 3, display a screen where the
503 first line of the display shall be some portion of:
504 (current last line) +1
507 otherwise, display a screen where the first line of the display shall
509 be some portion of:
510 (current first line) + count x ((window edit option) -2)
513 If this calculation would result in a line that is after the last line
515 of the edit buffer, the last line of the display shall display some
516 portion of the last line of the edit buffer.
517 Current line: If no lines from the previous display remain on the
519 screen, set to the first line of the display; otherwise, set to (line +
520 the number of new lines displayed on this screen).
521 Current column: Set to non-<blank>.
523 Display Information
525 Synopsis:
526 <control>-G
528 This command shall be equivalent to the ex file command.
530 Move Cursor Backwards
532 Synopsis:
533 [count] <control>-H
535 [count] h
536 the current erase character (see stty)
537 If there are no characters before the current character on the current
539 line, it shall be an error. If there are less than count previous char‐
540 acters on the current line, count shall be adjusted to the number of
541 previous characters on the line.
542 If used as a motion command:
544 1. The text region shall be from the character before the starting
546 cursor up to and including the countth character before the start‐
547 ing cursor.
548 2. Any text copied to a buffer shall be in character mode.
550 If not used as a motion command:
552 Current line: Unchanged.
554 Current column: Set to (column - the number of columns occupied by
556 count characters ending with the previous current column).
557 Move Down
559 Synopsis:
560 [count] <newline>
562 [count] <control>-J
563 [count] <control>-M
564 [count] <control>-N
565 [count] j
566 [count] <carriage-return>
567 [count] +
568 If there are less than count lines after the current line in the edit
570 buffer, it shall be an error.
571 If used as a motion command:
573 1. The text region shall include the starting line and the next count
575 - 1 lines.
576 2. Any text copied to a buffer shall be in line mode.
578 If not used as a motion command:
580 Current line: Set to current line+ count.
582 Current column: Set to non-<blank> for the <carriage-return>, <con‐
584 trol>‐M, and + commands; otherwise, unchanged.
585 Clear and Redisplay
587 Synopsis:
588 <control>-L
590 If in open mode, clear the screen and redisplay the current line. Oth‐
592 erwise, clear and redisplay the screen.
593 Current line: Unchanged.
595 Current column: Unchanged.
597 Move Up
599 Synopsis:
600 [count] <control>-P
602 [count] k
603 [count] -
604 If there are less than count lines before the current line in the edit
606 buffer, it shall be an error.
607 If used as a motion command:
609 1. The text region shall include the starting line and the previous
611 count lines.
612 2. Any text copied to a buffer shall be in line mode.
614 If not used as a motion command:
616 Current line: Set to current line - count.
618 Current column: Set to non-<blank> for the - command; otherwise,
620 unchanged.
621 Redraw Screen
623 Synopsis:
624 <control>-R
626 If any lines have been deleted from the display screen and flagged as
628 deleted on the terminal using the @ convention (see the beginning of
629 the EXTENDED DESCRIPTION section), they shall be redisplayed to match
630 the contents of the edit buffer.
631 It is unspecified whether lines flagged with @ because they do not fit
633 on the terminal display shall be affected.
634 Current line: Unchanged.
636 Current column: Unchanged.
638 Scroll Backward
640 Synopsis:
641 [count] <control>-U
643 If the current line is the first line of the edit buffer, it shall be
645 an error.
646 If no count is specified, count shall default to the count associated
648 with the previous <control>‐D or <control>‐U command. If there was no
649 previous <control>‐D or <control>‐U command, count shall default to the
650 value of the scroll edit option.
651 Current line: If count is greater than the current line, set to 1; oth‐
653 erwise, set to the current line - count.
654 Current column: Set to non-<blank>.
656 Scroll Backward by Line
658 Synopsis:
659 [count] <control>-Y
661 Display the line count lines before the first line currently displayed.
663 If the current line is the first line of the edit buffer, it shall be
665 an error. If this calculation would result in a line that is before the
666 first line of the edit buffer, the first line of the display shall dis‐
667 play some portion of the first line of the edit buffer.
668 Current line: Unchanged if the previous current character is displayed;
670 otherwise, set to the first line displayed.
671 Current column: Unchanged.
673 Edit the Alternate File
675 Synopsis:
676 <control>-^
678 This command shall be equivalent to the ex edit command, with the
680 alternate pathname as its argument.
681 Terminate Command or Input Mode
683 Synopsis:
684 <ESC>
686 If a partial vi command (as defined by at least one, non-count charac‐
688 ter) has been entered, discard the count and the command character(s).
689 Otherwise, if no command characters have been entered, and the <ESC>
691 was the result of a map expansion, the terminal shall be alerted and
692 the <ESC> character shall be discarded, but it shall not be an error.
693 Otherwise, it shall be an error.
695 Current line: Unchanged.
697 Current column: Unchanged.
699 Search for tagstring
701 Synopsis:
702 <control>-]
704 If the current character is not a word or <blank>, it shall be an
706 error.
707 This command shall be equivalent to the ex tag command, with the argu‐
709 ment to that command defined as follows.
710 If the current character is a <blank>:
712 1. Skip all <blank> characters after the cursor up to the end of the
714 line.
715 2. If the end of the line is reached, it shall be an error.
717 Then, the argument to the ex tag command shall be the current character
719 and all subsequent characters, up to the first non-word character or
720 the end of the line.
721 Move Cursor Forward
723 Synopsis:
724 [count] <space>
726 [count] l (ell)
727 If there are less than count non-<newline> characters after the cursor
729 on the current line, count shall be adjusted to the number of non-<new‐
730 line> characters after the cursor on the line.
731 If used as a motion command:
733 1. If the current or countth character after the cursor is the last
735 non-<newline> in the line, the text region shall be comprised of
736 the current character up to and including the last non-<newline> in
737 the line. Otherwise, the text region shall be from the current
738 character up to, but not including, the countth character after the
739 cursor.
740 2. Any text copied to a buffer shall be in character mode.
742 If not used as a motion command:
744 If there are no non-<newline> characters after the current character on
746 the current line, it shall be an error.
747 Current line: Unchanged.
749 Current column: Set to the last column that displays any portion of the
751 countth character after the current character.
752 Replace Text with Results from Shell Command
754 Synopsis:
755 [count] ! motion shell-commands <newline>
757 If the motion command is the ! command repeated:
759 1. If the edit buffer is empty and no count was supplied, the command
761 shall be the equivalent of the ex :read ! command, with the text
762 input, and no text shall be copied to any buffer.
763 2. Otherwise:
765 a. If there are less than count -1 lines after the current line in
767 the edit buffer, it shall be an error.
768 b. The text region shall be from the current line up to and
770 including the next count -1 lines.
771 Otherwise, the text region shall be the lines in which any character of
773 the text region specified by the motion command appear.
774 Any text copied to a buffer shall be in line mode.
776 This command shall be equivalent to the ex ! command for the specified
778 lines.
779 Move Cursor to End-of-Line
781 Synopsis:
782 [count] $
784 It shall be an error if there are less than (count -1) lines after the
786 current line in the edit buffer.
787 If used as a motion command:
789 1. If count is 1:
791 a. It shall be an error if the line is empty.
793 b. Otherwise, the text region shall consist of all characters from
795 the starting cursor to the last non-<newline> in the line,
796 inclusive, and any text copied to a buffer shall be in charac‐
797 ter mode.
798 2. Otherwise, if the starting cursor position is at or before the
800 first non-<blank> in the line, the text region shall consist of the
801 current and the next count -1 lines, and any text saved to a buffer
802 shall be in line mode.
803 3. Otherwise, the text region shall consist of all characters from the
805 starting cursor to the last non-<newline> in the line that is count
806 -1 lines forward from the current line, and any text copied to a
807 buffer shall be in character mode.
808 If not used as a motion command:
810 Current line: Set to the current line + count-1.
812 Current column: The current column is set to the last display line col‐
814 umn of the last non-<newline> in the line, or column position 1 if the
815 line is empty.
816 The current column shall be adjusted to be on the last display line
818 column of the last non-<newline> of the current line as subsequent com‐
819 mands change the current line, until a command changes the current col‐
820 umn.
821 Move to Matching Character
823 Synopsis:
824 %
826 If the character at the current position is not a parenthesis, bracket,
828 or curly brace, search forward in the line to the first one of those
829 characters. If no such character is found, it shall be an error.
830 The matching character shall be the parenthesis, bracket, or curly
832 brace matching the parenthesis, bracket, or curly brace, respectively,
833 that was at the current position or that was found on the current line.
834 Matching shall be determined as follows, for an open parenthesis:
836 1. Set a counter to 1.
838 2. Search forwards until a parenthesis is found or the end of the edit
840 buffer is reached.
841 3. If the end of the edit buffer is reached, it shall be an error.
843 4. If an open parenthesis is found, increment the counter by 1.
845 5. If a close parenthesis is found, decrement the counter by 1.
847 6. If the counter is zero, the current character is the matching char‐
849 acter.
850 Matching for a close parenthesis shall be equivalent, except that the
852 search shall be backwards, from the starting character to the beginning
853 of the buffer, a close parenthesis shall increment the counter by 1,
854 and an open parenthesis shall decrement the counter by 1.
855 Matching for brackets and curly braces shall be equivalent, except that
857 searching shall be done for open and close brackets or open and close
858 curly braces. It is implementation-defined whether other characters are
859 searched for and matched as well.
860 If used as a motion command:
862 1. If the matching cursor was after the starting cursor in the edit
864 buffer, and the starting cursor position was at or before the first
865 non-<blank> non-<newline> in the starting line, and the matching
866 cursor position was at or after the last non-<blank> non-<newline>
867 in the matching line, the text region shall consist of the current
868 line to the matching line, inclusive, and any text copied to a buf‐
869 fer shall be in line mode.
870 2. If the matching cursor was before the starting cursor in the edit
872 buffer, and the starting cursor position was at or after the last
873 non-<blank> non-<newline> in the starting line, and the matching
874 cursor position was at or before the first non-<blank> non-<new‐
875 line> in the matching line, the text region shall consist of the
876 current line to the matching line, inclusive, and any text copied
877 to a buffer shall be in line mode.
878 3. Otherwise, the text region shall consist of the starting character
880 to the matching character, inclusive, and any text copied to a buf‐
881 fer shall be in character mode.
882 If not used as a motion command:
884 Current line: Set to the line where the matching character is located.
886 Current column: Set to the last column where any portion of the match‐
888 ing character is displayed.
889 Repeat Substitution
891 Synopsis:
892 &
894 Repeat the previous substitution command. This command shall be equiva‐
896 lent to the ex & command with the current line as its addresses, and
897 without options, count, or flags.
898 Return to Previous Context at Beginning of Line
900 Synopsis:
901 ' character
903 It shall be an error if there is no line in the edit buffer marked by
905 character.
906 If used as a motion command:
908 1. If the starting cursor is after the marked cursor, then the loca‐
910 tions of the starting cursor and the marked cursor in the edit buf‐
911 fer shall be logically swapped.
912 2. The text region shall consist of the starting line up to and
914 including the marked line, and any text copied to a buffer shall be
915 in line mode.
916 If not used as a motion command:
918 Current line: Set to the line referenced by the mark.
920 Current column: Set to non-<blank>.
922 Return to Previous Context
924 Synopsis:
925 ` character
927 It shall be an error if the marked line is no longer in the edit buf‐
929 fer. If the marked line no longer contains a character in the saved
930 numbered character position, it shall be as if the marked position is
931 the first non-<blank>.
932 If used as a motion command:
934 1. It shall be an error if the marked cursor references the same char‐
936 acter in the edit buffer as the starting cursor.
937 2. If the starting cursor is after the marked cursor, then the loca‐
939 tions of the starting cursor and the marked cursor in the edit buf‐
940 fer shall be logically swapped.
941 3. If the starting line is empty or the starting cursor is at or
943 before the first non-<blank> non-<newline> of the starting line,
944 and the marked cursor line is empty or the marked cursor references
945 the first character of the marked cursor line, the text region
946 shall consist of all lines containing characters from the starting
947 cursor to the line before the marked cursor line, inclusive, and
948 any text copied to a buffer shall be in line mode.
949 4. Otherwise, if the marked cursor line is empty or the marked cursor
951 references a character at or before the first non-<blank> non-<new‐
952 line> of the marked cursor line, the region of text shall be from
953 the starting cursor to the last non-<newline> of the line before
954 the marked cursor line, inclusive, and any text copied to a buffer
955 shall be in character mode.
956 5. Otherwise, the region of text shall be from the starting cursor
958 (inclusive), to the marked cursor (exclusive), and any text copied
959 to a buffer shall be in character mode.
960 If not used as a motion command:
962 Current line: Set to the line referenced by the mark.
964 Current column: Set to the last column in which any portion of the
966 character referenced by the mark is displayed.
967 Return to Previous Section
969 Synopsis:
970 [count] [[
972 Move the cursor backward through the edit buffer to the first character
974 of the previous section boundary, count times.
975 If used as a motion command:
977 1. If the starting cursor was at the first character of the starting
979 line or the starting line was empty, and the first character of the
980 boundary was the first character of the boundary line, the text
981 region shall consist of the current line up to and including the
982 line where the countth next boundary starts, and any text copied to
983 a buffer shall be in line mode.
984 2. If the boundary was the last line of the edit buffer or the last
986 non-<newline> of the last line of the edit buffer, the text region
987 shall consist of the last character in the edit buffer up to and
988 including the starting character, and any text saved to a buffer
989 shall be in character mode.
990 3. Otherwise, the text region shall consist of the starting character
992 up to but not including the first character in the countth next
993 boundary, and any text copied to a buffer shall be in character
994 mode.
995 If not used as a motion command:
997 Current line: Set to the line where the countth next boundary in the
999 edit buffer starts.
1000 Current column: Set to the last column in which any portion of the
1002 first character of the countth next boundary is displayed, or column
1003 position 1 if the line is empty.
1004 Move to Next Section
1006 Synopsis:
1007 [count] ]]
1009 Move the cursor forward through the edit buffer to the first character
1011 of the next section boundary, count times.
1012 If used as a motion command:
1014 1. If the starting cursor was at the first character of the starting
1016 line or the starting line was empty, and the first character of the
1017 boundary was the first character of the boundary line, the text
1018 region shall consist of the current line up to and including the
1019 line where the countth previous boundary starts, and any text
1020 copied to a buffer shall be in line mode.
1021 2. If the boundary was the first line of the edit buffer, the text
1023 region shall consist of the first character in the edit buffer up
1024 to but not including the starting character, and any text copied to
1025 a buffer shall be in character mode.
1026 3. Otherwise, the text region shall consist of the first character in
1028 the countth previous section boundary up to but not including the
1029 starting character, and any text copied to a buffer shall be in
1030 character mode.
1031 If not used as a motion command:
1033 Current line: Set to the line where the countth previous boundary in
1035 the edit buffer starts.
1036 Current column: Set to the last column in which any portion of the
1038 first character of the countth previous boundary is displayed, or col‐
1039 umn position 1 if the line is empty.
1040 Move to First Non-<blank> Position on Current Line
1042 Synopsis:
1043 ^
1045 If used as a motion command:
1047 1. If the line has no non-<blank> non-<newline> characters, or if the
1049 cursor is at the first non-<blank> non-<newline> of the line, it
1050 shall be an error.
1051 2. If the cursor is before the first non-<blank> non-<newline> of the
1053 line, the text region shall be comprised of the current character,
1054 up to, but not including, the first non-<blank> non-<newline> of
1055 the line.
1056 3. If the cursor is after the first non-<blank> non-<newline> of the
1058 line, the text region shall be from the character before the start‐
1059 ing cursor up to and including the first non-<blank> non-<newline>
1060 of the line.
1061 4. Any text copied to a buffer shall be in character mode.
1063 If not used as a motion command:
1065 Current line: Unchanged.
1067 Current column: Set to non-<blank>.
1069 Current and Line Above
1071 Synopsis:
1072 [count] _
1074 If there are less than count -1 lines after the current line in the
1076 edit buffer, it shall be an error.
1077 If used as a motion command:
1079 1. If count is less than 2, the text region shall be the current line.
1081 2. Otherwise, the text region shall include the starting line and the
1083 next count -1 lines.
1084 3. Any text copied to a buffer shall be in line mode.
1086 If not used as a motion command:
1088 Current line: Set to current line + count -1.
1090 Current column: Set to non-<blank>.
1092 Move Back to Beginning of Sentence
1094 Synopsis:
1095 [count] (
1097 Move backward to the beginning of a sentence. This command shall be
1099 equivalent to the [[ command, with the exception that sentence bound‐
1100 aries shall be used instead of section boundaries.
1101 Move Forward to Beginning of Sentence
1103 Synopsis:
1104 [count] )
1106 Move forward to the beginning of a sentence. This command shall be
1108 equivalent to the ]] command, with the exception that sentence bound‐
1109 aries shall be used instead of section boundaries.
1110 Move Back to Preceding Paragraph
1112 Synopsis:
1113 [count] {
1115 Move back to the beginning of the preceding paragraph. This command
1117 shall be equivalent to the [[ command, with the exception that para‐
1118 graph boundaries shall be used instead of section boundaries.
1119 Move Forward to Next Paragraph
1121 Synopsis:
1122 [count] }
1124 Move forward to the beginning of the next paragraph. This command shall
1126 be equivalent to the ]] command, with the exception that paragraph
1127 boundaries shall be used instead of section boundaries.
1128 Move to Specific Column Position
1130 Synopsis:
1131 [count] |
1133 For the purposes of this command, lines that are too long for the cur‐
1135 rent display and that have been folded shall be treated as having a
1136 single, 1-based, number of columns.
1137 If there are less than count columns in which characters from the cur‐
1139 rent line are displayed on the screen, count shall be adjusted to be
1140 the last column in which any portion of the line is displayed on the
1141 screen.
1142 If used as a motion command:
1144 1. If the line is empty, or the cursor character is the same as the
1146 character on the countth column of the line, it shall be an error.
1147 2. If the cursor is before the countth column of the line, the text
1149 region shall be comprised of the current character, up to but not
1150 including the character on the countth column of the line.
1151 3. If the cursor is after the countth column of the line, the text
1153 region shall be from the character before the starting cursor up to
1154 and including the character on the countth column of the line.
1155 4. Any text copied to a buffer shall be in character mode.
1157 If not used as a motion command:
1159 Current line: Unchanged.
1161 Current column: Set to the last column in which any portion of the
1163 character that is displayed in the count column of the line is dis‐
1164 played.
1165 Reverse Find Character
1167 Synopsis:
1168 [count] ,
1170 If the last F, f, T, or t command was F, f, T, or t, this command shall
1172 be equivalent to an f, F, t, or T command, respectively, with the spec‐
1173 ified count and the same search character.
1174 If there was no previous F, f, T, or t command, it shall be an error.
1176 Repeat
1178 Synopsis:
1179 [count] .
1181 Repeat the last !, <, >, A, C, D, I, J, O, P, R, S, X, Y, a, c, d, i,
1183 o, p, r, s, x, y, or ~ command. It shall be an error if none of these
1184 commands have been executed. Commands (other than commands that enter
1185 text input mode) executed as a result of map expansions, shall not
1186 change the value of the last repeatable command.
1187 Repeated commands with associated motion commands shall repeat the
1189 motion command as well; however, any specified count shall replace the
1190 count(s) that were originally specified to the repeated command or its
1191 associated motion command.
1192 If the motion component of the repeated command is f, F, t, or T, the
1194 repeated command shall not set the remembered search character for the
1195 ; and , commands.
1196 If the repeated command is p or P, and the buffer associated with that
1198 command was a numeric buffer named with a number less than 9, the buf‐
1199 fer associated with the repeated command shall be set to be the buffer
1200 named by the name of the previous buffer logically incremented by 1.
1201 If the repeated character is a text input command, the input text asso‐
1203 ciated with that command is repeated literally:
1204 * Input characters are neither macro or abbreviation-expanded.
1206 * Input characters are not interpreted in any special way with the
1208 exception that <newline>, <carriage-return>, and <control>‐T behave
1209 as described in Input Mode Commands in vi.
1210 Current line: Set as described for the repeated command.
1212 Current column: Set as described for the repeated command.
1214 Find Regular Expression
1216 Synopsis:
1217 /
1219 If the input line contains no non-<newline> characters, it shall be
1221 equivalent to a line containing only the last regular expression
1222 encountered. The enhanced regular expressions supported by vi are
1223 described in Regular Expressions in ex.
1224 Otherwise, the line shall be interpreted as one or more regular expres‐
1226 sions, optionally followed by an address offset or a vi z command.
1227 If the regular expression is not the last regular expression on the
1229 line, or if a line offset or z command is specified, the regular
1230 expression shall be terminated by an unescaped '/' character, which
1231 shall not be used as part of the regular expression. If the regular
1232 expression is not the first regular expression on the line, it shall be
1233 preceded by zero or more <blank> characters, a <semicolon>, zero or
1234 more <blank> characters, and a leading '/' character, which shall not
1235 be interpreted as part of the regular expression. It shall be an error
1236 to precede any regular expression with any characters other than these.
1237 Each search shall begin from the character after the first character of
1239 the last match (or, if it is the first search, after the cursor). If
1240 the wrapscan edit option is set, the search shall continue to the char‐
1241 acter before the starting cursor character; otherwise, to the end of
1242 the edit buffer. It shall be an error if any search fails to find a
1243 match, and an informational message to this effect shall be displayed.
1244 An optional address offset (see Addressing in ex) can be specified
1246 after the last regular expression by including a trailing '/' character
1247 after the regular expression and specifying the address offset. This
1248 offset will be from the line containing the match for the last regular
1249 expression specified. It shall be an error if the line offset would
1250 indicate a line address less than 1 or greater than the last line in
1251 the edit buffer. An address offset of zero shall be supported. It shall
1252 be an error to follow the address offset with any other characters than
1253 <blank> characters.
1254 If not used as a motion command, an optional z command (see Redraw Win‐
1256 dow) can be specified after the last regular expression by including a
1257 trailing '/' character after the regular expression, zero or more
1258 <blank> characters, a 'z', zero or more <blank> characters, an optional
1259 new window edit option value, zero or more <blank> characters, and a
1260 location character. The effect shall be as if the z command was exe‐
1261 cuted after the / command. It shall be an error to follow the z command
1262 with any other characters than <blank> characters.
1263 The remembered search direction shall be set to forward.
1265 If used as a motion command:
1267 1. It shall be an error if the last match references the same charac‐
1269 ter in the edit buffer as the starting cursor.
1270 2. If any address offset is specified, the last match shall be
1272 adjusted by the specified offset as described previously.
1273 3. If the starting cursor is after the last match, then the locations
1275 of the starting cursor and the last match in the edit buffer shall
1276 be logically swapped.
1277 4. If any address offset is specified, the text region shall consist
1279 of all lines containing characters from the starting cursor to the
1280 last match line, inclusive, and any text copied to a buffer shall
1281 be in line mode.
1282 5. Otherwise, if the starting line is empty or the starting cursor is
1284 at or before the first non-<blank> non-<newline> of the starting
1285 line, and the last match line is empty or the last match starts at
1286 the first character of the last match line, the text region shall
1287 consist of all lines containing characters from the starting cursor
1288 to the line before the last match line, inclusive, and any text
1289 copied to a buffer shall be in line mode.
1290 6. Otherwise, if the last match line is empty or the last match begins
1292 at a character at or before the first non-<blank> non-<newline> of
1293 the last match line, the region of text shall be from the current
1294 cursor to the last non-<newline> of the line before the last match
1295 line, inclusive, and any text copied to a buffer shall be in char‐
1296 acter mode.
1297 7. Otherwise, the region of text shall be from the current cursor
1299 (inclusive), to the first character of the last match (exclusive),
1300 and any text copied to a buffer shall be in character mode.
1301 If not used as a motion command:
1303 Current line: If a match is found, set to the last matched line plus
1305 the address offset, if any; otherwise, unchanged.
1306 Current column: Set to the last column on which any portion of the
1308 first character in the last matched string is displayed, if a match is
1309 found; otherwise, unchanged.
1310 Move to First Character in Line
1312 Synopsis:
1313 0 (zero)
1315 Move to the first character on the current line. The character '0'
1317 shall not be interpreted as a command if it is immediately preceded by
1318 a digit.
1319 If used as a motion command:
1321 1. If the cursor character is the first character in the line, it
1323 shall be an error.
1324 2. The text region shall be from the character before the cursor char‐
1326 acter up to and including the first character in the line.
1327 3. Any text copied to a buffer shall be in character mode.
1329 If not used as a motion command:
1331 Current line: Unchanged.
1333 Current column: The last column in which any portion of the first char‐
1335 acter in the line is displayed, or if the line is empty, unchanged.
1336 Execute an ex Command
1338 Synopsis:
1339 :
1341 Execute one or more ex commands.
1343 If any portion of the screen other than the last line of the screen was
1345 overwritten by any ex command (except shell), vi shall display a mes‐
1346 sage indicating that it is waiting for an input from the user, and
1347 shall then read a character. This action may also be taken for other,
1348 unspecified reasons.
1349 If the next character entered is a ':', another ex command shall be
1351 accepted and executed. Any other character shall cause the screen to be
1352 refreshed and vi shall return to command mode.
1353 Current line: As specified for the ex command.
1355 Current column: As specified for the ex command.
1357 Repeat Find
1359 Synopsis:
1360 [count] ;
1362 This command shall be equivalent to the last F, f, T, or t command,
1364 with the specified count, and with the same search character used for
1365 the last F, f, T, or t command. If there was no previous F, f, T, or t
1366 command, it shall be an error.
1367 Shift Left
1369 Synopsis:
1370 [count] < motion
1372 If the motion command is the < command repeated:
1374 1. If there are less than count -1 lines after the current line in the
1376 edit buffer, it shall be an error.
1377 2. The text region shall be from the current line, up to and including
1379 the next count -1 lines.
1380 Shift any line in the text region specified by the count and motion
1382 command one shiftwidth (see the ex shiftwidth option) toward the start
1383 of the line, as described by the ex < command. The unshifted lines
1384 shall be copied to the unnamed buffer in line mode.
1385 Current line: If the motion was from the current cursor position toward
1387 the end of the edit buffer, unchanged. Otherwise, set to the first line
1388 in the edit buffer that is part of the text region specified by the
1389 motion command.
1390 Current column: Set to non-<blank>.
1392 Shift Right
1394 Synopsis:
1395 [count] > motion
1397 If the motion command is the > command repeated:
1399 1. If there are less than count -1 lines after the current line in the
1401 edit buffer, it shall be an error.
1402 2. The text region shall be from the current line, up to and including
1404 the next count -1 lines.
1405 Shift any line with characters in the text region specified by the
1407 count and motion command one shiftwidth (see the ex shiftwidth option)
1408 away from the start of the line, as described by the ex > command. The
1409 unshifted lines shall be copied into the unnamed buffer in line mode.
1410 Current line: If the motion was from the current cursor position toward
1412 the end of the edit buffer, unchanged. Otherwise, set to the first line
1413 in the edit buffer that is part of the text region specified by the
1414 motion command.
1415 Current column: Set to non-<blank>.
1417 Scan Backwards for Regular Expression
1419 Synopsis:
1420 ?
1422 Scan backwards; the ? command shall be equivalent to the / command
1424 (see Find Regular Expression) with the following exceptions:
1425 1. The input prompt shall be a '?'.
1427 2. Each search shall begin from the character before the first charac‐
1429 ter of the last match (or, if it is the first search, the character
1430 before the cursor character).
1431 3. The search direction shall be from the cursor toward the beginning
1433 of the edit buffer, and the wrapscan edit option shall affect
1434 whether the search wraps to the end of the edit buffer and contin‐
1435 ues.
1436 4. The remembered search direction shall be set to backward.
1438 Execute
1440 Synopsis:
1441 @buffer
1443 If the buffer is specified as @, the last buffer executed shall be
1445 used. If no previous buffer has been executed, it shall be an error.
1446 Behave as if the contents of the named buffer were entered as standard
1448 input. After each line of a line-mode buffer, and all but the last line
1449 of a character mode buffer, behave as if a <newline> were entered as
1450 standard input.
1451 If an error occurs during this process, an error message shall be writ‐
1453 ten, and no more characters resulting from the execution of this com‐
1454 mand shall be processed.
1455 If a count is specified, behave as if that count were entered as user
1457 input before the characters from the @ buffer were entered.
1458 Current line: As specified for the individual commands.
1460 Current column: As specified for the individual commands.
1462 Reverse Case
1464 Synopsis:
1465 [count] ~
1467 Reverse the case of the current character and the next count -1 charac‐
1469 ters, such that lowercase characters that have uppercase counterparts
1470 shall be changed to uppercase characters, and uppercase characters that
1471 have lowercase counterparts shall be changed to lowercase characters,
1472 as prescribed by the current locale. No other characters shall be
1473 affected by this command.
1474 If there are less than count -1 characters after the cursor in the edit
1476 buffer, count shall be adjusted to the number of characters after the
1477 cursor in the edit buffer minus 1.
1478 For the purposes of this command, the next character after the last
1480 non-<newline> on the line shall be the next character in the edit buf‐
1481 fer.
1482 Current line: Set to the line including the (count-1)th character after
1484 the cursor.
1485 Current column: Set to the last column in which any portion of the
1487 (count-1)th character after the cursor is displayed.
1488 Append
1490 Synopsis:
1491 [count] a
1493 Enter text input mode after the current cursor position. No characters
1495 already in the edit buffer shall be affected by this command. A count
1496 shall cause the input text to be appended count -1 more times to the
1497 end of the input.
1498 Current line/column: As specified for the text input commands (see
1500 Input Mode Commands in vi).
1501 Append at End-of-Line
1503 Synopsis:
1504 [count] A
1506 This command shall be equivalent to the vi command:
1508 $ [ count ] a
1511 (see Append).
1513 Move Backward to Preceding Word
1515 Synopsis:
1516 [count] b
1518 With the exception that words are used as the delimiter instead of big‐
1520 words, this command shall be equivalent to the B command.
1521 Move Backward to Preceding Bigword
1523 Synopsis:
1524 [count] B
1526 If the edit buffer is empty or the cursor is on the first character of
1528 the edit buffer, it shall be an error. If less than count bigwords
1529 begin between the cursor and the start of the edit buffer, count shall
1530 be adjusted to the number of bigword beginnings between the cursor and
1531 the start of the edit buffer.
1532 If used as a motion command:
1534 1. The text region shall be from the first character of the countth
1536 previous bigword beginning up to but not including the cursor char‐
1537 acter.
1538 2. Any text copied to a buffer shall be in character mode.
1540 If not used as a motion command:
1542 Current line: Set to the line containing the current column.
1544 Current column: Set to the last column upon which any part of the first
1546 character of the countth previous bigword is displayed.
1547 Change
1549 Synopsis:
1550 [buffer][count] c motion
1552 If the motion command is the c command repeated:
1554 1. The buffer text shall be in line mode.
1556 2. If there are less than count -1 lines after the current line in the
1558 edit buffer, it shall be an error.
1559 3. The text region shall be from the current line up to and including
1561 the next count -1 lines.
1562 Otherwise, the buffer text mode and text region shall be as specified
1564 by the motion command.
1565 The replaced text shall be copied into buffer, if specified, and into
1567 the unnamed buffer. If the text to be replaced contains characters from
1568 more than a single line, or the buffer text is in line mode, the
1569 replaced text shall be copied into the numeric buffers as well.
1570 If the buffer text is in line mode:
1572 1. Any lines that contain characters in the region shall be deleted,
1574 and the editor shall enter text input mode at the beginning of a
1575 new line which shall replace the first line deleted.
1576 2. If the autoindent edit option is set, autoindent characters equal
1578 to the autoindent characters on the first line deleted shall be
1579 inserted as if entered by the user.
1580 Otherwise, if characters from more than one line are in the region of
1582 text:
1583 1. The text shall be deleted.
1585 2. Any text remaining in the last line in the text region shall be
1587 appended to the first line in the region, and the last line in the
1588 region shall be deleted.
1589 3. The editor shall enter text input mode after the last character not
1591 deleted from the first line in the text region, if any; otherwise,
1592 on the first column of the first line in the region.
1593 Otherwise:
1595 1. If the glyph for '$' is smaller than the region, the end of the
1597 region shall be marked with a '$'.
1598 2. The editor shall enter text input mode, overwriting the region of
1600 text.
1601 Current line/column: As specified for the text input commands (see
1603 Input Mode Commands in vi).
1604 Change to End-of-Line
1606 Synopsis:
1607 [buffer][count] C
1609 This command shall be equivalent to the vi command:
1611 [buffer][count] c$
1614 See the c command.
1616 Delete
1618 Synopsis:
1619 [buffer][count] d motion
1621 If the motion command is the d command repeated:
1623 1. The buffer text shall be in line mode.
1625 2. If there are less than count -1 lines after the current line in the
1627 edit buffer, it shall be an error.
1628 3. The text region shall be from the current line up to and including
1630 the next count -1 lines.
1631 Otherwise, the buffer text mode and text region shall be as specified
1633 by the motion command.
1634 If in open mode, and the current line is deleted, and the line remains
1636 on the display, an '@' character shall be displayed as the first glyph
1637 of that line.
1638 Delete the region of text into buffer, if specified, and into the
1640 unnamed buffer. If the text to be deleted contains characters from more
1641 than a single line, or the buffer text is in line mode, the deleted
1642 text shall be copied into the numeric buffers, as well.
1643 Current line: Set to the first text region line that appears in the
1645 edit buffer, unless that line has been deleted, in which case it shall
1646 be set to the last line in the edit buffer, or line 1 if the edit buf‐
1647 fer is empty.
1648 Current column:
1650 1. If the line is empty, set to column position 1.
1652 2. Otherwise, if the buffer text is in line mode or the motion was
1654 from the cursor toward the end of the edit buffer:
1655 a. If a character from the current line is displayed in the cur‐
1657 rent column, set to the last column that displays any portion
1658 of that character.
1659 b. Otherwise, set to the last column in which any portion of any
1661 character in the line is displayed.
1662 3. Otherwise, if a character is displayed in the column that began the
1664 text region, set to the last column that displays any portion of
1665 that character.
1666 4. Otherwise, set to the last column in which any portion of any char‐
1668 acter in the line is displayed.
1669 Delete to End-of-Line
1671 Synopsis:
1672 [buffer] D
1674 Delete the text from the current position to the end of the current
1676 line; equivalent to the vi command:
1677 [buffer] d$
1680 Move to End-of-Word
1682 Synopsis:
1683 [count] e
1685 With the exception that words are used instead of bigwords as the
1687 delimiter, this command shall be equivalent to the E command.
1688 Move to End-of-Bigword
1690 Synopsis:
1691 [count] E
1693 If the edit buffer is empty it shall be an error. If less than count
1695 bigwords end between the cursor and the end of the edit buffer, count
1696 shall be adjusted to the number of bigword endings between the cursor
1697 and the end of the edit buffer.
1698 If used as a motion command:
1700 1. The text region shall be from the last character of the countth
1702 next bigword up to and including the cursor character.
1703 2. Any text copied to a buffer shall be in character mode.
1705 If not used as a motion command:
1707 Current line: Set to the line containing the current column.
1709 Current column: Set to the last column upon which any part of the last
1711 character of the countth next bigword is displayed.
1712 Find Character in Current Line (Forward)
1714 Synopsis:
1715 [count] f character
1717 It shall be an error if count occurrences of the character do not occur
1719 after the cursor in the line.
1720 If used as a motion command:
1722 1. The text range shall be from the cursor character up to and includ‐
1724 ing the countth occurrence of the specified character after the
1725 cursor.
1726 2. Any text copied to a buffer shall be in character mode.
1728 If not used as a motion command:
1730 Current line: Unchanged.
1732 Current column: Set to the last column in which any portion of the
1734 countth occurrence of the specified character after the cursor appears
1735 in the line.
1736 Find Character in Current Line (Reverse)
1738 Synopsis:
1739 [count] F character
1741 It shall be an error if count occurrences of the character do not occur
1743 before the cursor in the line.
1744 If used as a motion command:
1746 1. The text region shall be from the countth occurrence of the speci‐
1748 fied character before the cursor, up to, but not including the cur‐
1749 sor character.
1750 2. Any text copied to a buffer shall be in character mode.
1752 If not used as a motion command:
1754 Current line: Unchanged.
1756 Current column: Set to the last column in which any portion of the
1758 countth occurrence of the specified character before the cursor appears
1759 in the line.
1760 Move to Line
1762 Synopsis:
1763 [count] G
1765 If count is not specified, it shall default to the last line of the
1767 edit buffer. If count is greater than the last line of the edit buf‐
1768 fer, it shall be an error.
1769 If used as a motion command:
1771 1. The text region shall be from the cursor line up to and including
1773 the specified line.
1774 2. Any text copied to a buffer shall be in line mode.
1776 If not used as a motion command:
1778 Current line: Set to count if count is specified; otherwise, the last
1780 line.
1781 Current column: Set to non-<blank>.
1783 Move to Top of Screen
1785 Synopsis:
1786 [count] H
1788 If the beginning of the line count greater than the first line of which
1790 any portion appears on the display does not exist, it shall be an
1791 error.
1792 If used as a motion command:
1794 1. If in open mode, the text region shall be the current line.
1796 2. Otherwise, the text region shall be from the starting line up to
1798 and including (the first line of the display + count -1).
1799 3. Any text copied to a buffer shall be in line mode.
1801 If not used as a motion command:
1803 If in open mode, this command shall set the current column to
1805 non-<blank> and do nothing else.
1806 Otherwise, it shall set the current line and current column as follows.
1808 Current line: Set to (the first line of the display + count -1).
1810 Current column: Set to non-<blank>.
1812 Insert Before Cursor
1814 Synopsis:
1815 [count] i
1817 Enter text input mode before the current cursor position. No characters
1819 already in the edit buffer shall be affected by this command. A count
1820 shall cause the input text to be appended count -1 more times to the
1821 end of the input.
1822 Current line/column: As specified for the text input commands (see
1824 Input Mode Commands in vi).
1825 Insert at Beginning of Line
1827 Synopsis:
1828 [count] I
1830 This command shall be equivalent to the vi command ^[count]i.
1832 Join
1834 Synopsis:
1835 [count] J
1837 If the current line is the last line in the edit buffer, it shall be an
1839 error.
1840 This command shall be equivalent to the ex join command with no
1842 addresses, and an ex command count value of 1 if count was not speci‐
1843 fied or if a count of 1 was specified, and an ex command count value of
1844 count -1 for any other value of count, except that the current line and
1845 column shall be set as follows.
1846 Current line: Unchanged.
1848 Current column: The last column in which any portion of the character
1850 following the last character in the initial line is displayed, or the
1851 last non-<newline> in the line if no characters were appended.
1852 Move to Bottom of Screen
1854 Synopsis:
1855 [count] L
1857 If the beginning of the line count less than the last line of which any
1859 portion appears on the display does not exist, it shall be an error.
1860 If used as a motion command:
1862 1. If in open mode, the text region shall be the current line.
1864 2. Otherwise, the text region shall include all lines from the start‐
1866 ing cursor line to (the last line of the display -(count -1)).
1867 3. Any text copied to a buffer shall be in line mode.
1869 If not used as a motion command:
1871 1. If in open mode, this command shall set the current column to
1873 non-<blank> and do nothing else.
1874 2. Otherwise, it shall set the current line and current column as fol‐
1876 lows.
1877 Current line: Set to (the last line of the display -(count -1)).
1879 Current column: Set to non-<blank>.
1881 Mark Position
1883 Synopsis:
1884 m letter
1886 This command shall be equivalent to the ex mark command with the speci‐
1888 fied character as an argument.
1889 Move to Middle of Screen
1891 Synopsis:
1892 M
1894 The middle line of the display shall be calculated as follows:
1896 (the top line of the display) + (((number of lines displayed) +1) /2) -1
1899 If used as a motion command:
1901 1. If in open mode, the text region shall be the current line.
1903 2. Otherwise, the text region shall include all lines from the start‐
1905 ing cursor line up to and including the middle line of the display.
1906 3. Any text copied to a buffer shall be in line mode.
1908 If not used as a motion command:
1910 If in open mode, this command shall set the current column to
1912 non-<blank> and do nothing else.
1913 Otherwise, it shall set the current line and current column as follows.
1915 Current line: Set to the middle line of the display.
1917 Current column: Set to non-<blank>.
1919 Repeat Regular Expression Find (Forward)
1921 Synopsis:
1922 n
1924 If the remembered search direction was forward, the n command shall be
1926 equivalent to the vi / command with no characters entered by the user.
1927 Otherwise, it shall be equivalent to the vi ? command with no charac‐
1928 ters entered by the user.
1929 If the n command is used as a motion command for the ! command, the
1931 editor shall not enter text input mode on the last line on the screen,
1932 and shall behave as if the user entered a single '!' character as the
1933 text input.
1934 Repeat Regular Expression Find (Reverse)
1936 Synopsis:
1937 N
1939 Scan for the next match of the last pattern given to / or ?, but in the
1941 reverse direction; this is the reverse of n.
1942 If the remembered search direction was forward, the N command shall be
1944 equivalent to the vi ? command with no characters entered by the user.
1945 Otherwise, it shall be equivalent to the vi / command with no charac‐
1946 ters entered by the user. If the N command is used as a motion command
1947 for the ! command, the editor shall not enter text input mode on the
1948 last line on the screen, and shall behave as if the user entered a sin‐
1949 gle ! character as the text input.
1950 Insert Empty Line Below
1952 Synopsis:
1953 o
1955 Enter text input mode in a new line appended after the current line. A
1957 count shall cause the input text to be appended count -1 more times to
1958 the end of the already added text, each time starting on a new,
1959 appended line.
1960 Current line/column: As specified for the text input commands (see
1962 Input Mode Commands in vi).
1963 Insert Empty Line Above
1965 Synopsis:
1966 O
1968 Enter text input mode in a new line inserted before the current line. A
1970 count shall cause the input text to be appended count -1 more times to
1971 the end of the already added text, each time starting on a new,
1972 appended line.
1973 Current line/column: As specified for the text input commands (see
1975 Input Mode Commands in vi).
1976 Put from Buffer Following
1978 Synopsis:
1979 [buffer] p
1981 If no buffer is specified, the unnamed buffer shall be used.
1983 If the buffer text is in line mode, the text shall be appended below
1985 the current line, and each line of the buffer shall become a new line
1986 in the edit buffer. A count shall cause the buffer text to be appended
1987 count -1 more times to the end of the already added text, each time
1988 starting on a new, appended line.
1989 If the buffer text is in character mode, the text shall be appended
1991 into the current line after the cursor, and each line of the buffer
1992 other than the first and last shall become a new line in the edit buf‐
1993 fer. A count shall cause the buffer text to be appended count -1 more
1994 times to the end of the already added text, each time starting after
1995 the last added character.
1996 Current line: If the buffer text is in line mode, set the line to line
1998 +1; otherwise, unchanged.
1999 Current column: If the buffer text is in line mode:
2001 1. If there is a non-<blank> in the first line of the buffer, set to
2003 the last column on which any portion of the first non-<blank> in
2004 the line is displayed.
2005 2. If there is no non-<blank> in the first line of the buffer, set to
2007 the last column on which any portion of the last non-<newline> in
2008 the first line of the buffer is displayed.
2009 If the buffer text is in character mode:
2011 1. If the text in the buffer is from more than a single line, then set
2013 to the last column on which any portion of the first character from
2014 the buffer is displayed.
2015 2. Otherwise, if the buffer is the unnamed buffer, set to the last
2017 column on which any portion of the last character from the buffer
2018 is displayed.
2019 3. Otherwise, set to the first column on which any portion of the
2021 first character from the buffer is displayed.
2022 Put from Buffer Before
2024 Synopsis:
2025 [buffer] P
2027 If no buffer is specified, the unnamed buffer shall be used.
2029 If the buffer text is in line mode, the text shall be inserted above
2031 the current line, and each line of the buffer shall become a new line
2032 in the edit buffer. A count shall cause the buffer text to be appended
2033 count -1 more times to the end of the already added text, each time
2034 starting on a new, appended line.
2035 If the buffer text is in character mode, the text shall be inserted
2037 into the current line before the cursor, and each line of the buffer
2038 other than the first and last shall become a new line in the edit buf‐
2039 fer. A count shall cause the buffer text to be appended count -1 more
2040 times to the end of the already added text, each time starting after
2041 the last added character.
2042 Current line: Unchanged.
2044 Current column: If the buffer text is in line mode:
2046 1. If there is a non-<blank> in the first line of the buffer, set to
2048 the last column on which any portion of that character is dis‐
2049 played.
2050 2. If there is no non-<blank> in the first line of the buffer, set to
2052 the last column on which any portion of the last non-<newline> in
2053 the first line of the buffer is displayed.
2054 If the buffer text is in character mode:
2056 1. If the text in the buffer is from more than a single line, then set
2058 to the last column on which any portion of the first character from
2059 the buffer is displayed.
2060 2. Otherwise, if the buffer is the unnamed buffer, set to the last
2062 column on which any portion of the last character from the buffer
2063 is displayed.
2064 3. Otherwise, set to the first column on which any portion of the
2066 first character from the buffer is displayed.
2067 Enter ex Mode
2069 Synopsis:
2070 Q
2072 Leave visual or open mode and enter ex command mode.
2074 Current line: Unchanged.
2076 Current column: Unchanged.
2078 Replace Character
2080 Synopsis:
2081 [count] r character
2083 Replace the count characters at and after the cursor with the specified
2085 character. If there are less than count non-<newline> characters at and
2086 after the cursor on the line, it shall be an error.
2087 If character is <control>‐V, any next character other than the <new‐
2089 line> shall be stripped of any special meaning and used as a literal
2090 character.
2091 If character is <ESC>, no replacement shall be made and the current
2093 line and current column shall be unchanged.
2094 If character is <carriage-return> or <newline>, count new lines shall
2096 be appended to the current line. All but the last of these lines shall
2097 be empty. count characters at and after the cursor shall be discarded,
2098 and any remaining characters after the cursor in the current line shall
2099 be moved to the last of the new lines. If the autoindent edit option is
2100 set, they shall be preceded by the same number of autoindent characters
2101 found on the line from which the command was executed.
2102 Current line: Unchanged unless the replacement character is a <car‐
2104 riage-return> or <newline>, in which case it shall be set to line +
2105 count.
2106 Current column: Set to the last column position on which a portion of
2108 the last replaced character is displayed, or if the replacement charac‐
2109 ter caused new lines to be created, set to non-<blank>.
2110 Replace Characters
2112 Synopsis:
2113 R
2115 Enter text input mode at the current cursor position possibly replacing
2117 text on the current line. A count shall cause the input text to be
2118 appended count -1 more times to the end of the input.
2119 Current line/column: As specified for the text input commands (see
2121 Input Mode Commands in vi).
2122 Substitute Character
2124 Synopsis:
2125 [buffer][count] s
2127 This command shall be equivalent to the vi command:
2129 [buffer][count] c<space>
2132 Substitute Lines
2134 Synopsis:
2135 [buffer][count] S
2137 This command shall be equivalent to the vi command:
2139 [buffer][count] c_
2142 Move Cursor to Before Character (Forward)
2144 Synopsis:
2145 [count] t character
2147 It shall be an error if count occurrences of the character do not occur
2149 after the cursor in the line.
2150 If used as a motion command:
2152 1. The text region shall be from the cursor up to but not including
2154 the countth occurrence of the specified character after the cursor.
2155 2. Any text copied to a buffer shall be in character mode.
2157 If not used as a motion command:
2159 Current line: Unchanged.
2161 Current column: Set to the last column in which any portion of the
2163 character before the countth occurrence of the specified character
2164 after the cursor appears in the line.
2165 Move Cursor to After Character (Reverse)
2167 Synopsis:
2168 [count] T character
2170 It shall be an error if count occurrences of the character do not occur
2172 before the cursor in the line.
2173 If used as a motion command:
2175 1. If the character before the cursor is the specified character, it
2177 shall be an error.
2178 2. The text region shall be from the character before the cursor up to
2180 but not including the countth occurrence of the specified character
2181 before the cursor.
2182 3. Any text copied to a buffer shall be in character mode.
2184 If not used as a motion command:
2186 Current line: Unchanged.
2188 Current column: Set to the last column in which any portion of the
2190 character after the countth occurrence of the specified character
2191 before the cursor appears in the line.
2192 Undo
2194 Synopsis:
2195 u
2197 This command shall be equivalent to the ex undo command except that the
2199 current line and current column shall be set as follows:
2200 Current line: Set to the first line added or changed if any; otherwise,
2202 move to the line preceding any deleted text if one exists; otherwise,
2203 move to line 1.
2204 Current column: If undoing an ex command, set to the first non-<blank>.
2206 Otherwise, if undoing a text input command:
2208 1. If the command was a C, c, O, o, R, S, or s command, the current
2210 column shall be set to the value it held when the text input com‐
2211 mand was entered.
2212 2. Otherwise, set to the last column in which any portion of the first
2214 character after the deleted text is displayed, or, if no non-<new‐
2215 line> characters follow the text deleted from this line, set to the
2216 last column in which any portion of the last non-<newline> in the
2217 line is displayed, or 1 if the line is empty.
2218 Otherwise, if a single line was modified (that is, not added or
2220 deleted) by the u command:
2221 1. If text was added or changed, set to the last column in which any
2223 portion of the first character added or changed is displayed.
2224 2. If text was deleted, set to the last column in which any portion of
2226 the first character after the deleted text is displayed, or, if no
2227 non-<newline> characters follow the deleted text, set to the last
2228 column in which any portion of the last non-<newline> in the line
2229 is displayed, or 1 if the line is empty.
2230 Otherwise, set to non-<blank>.
2232 Undo Current Line
2234 Synopsis:
2235 U
2237 Restore the current line to its state immediately before the most
2239 recent time that it became the current line.
2240 Current line: Unchanged.
2242 Current column: Set to the first column in the line in which any por‐
2244 tion of the first character in the line is displayed.
2245 Move to Beginning of Word
2247 Synopsis:
2248 [count] w
2250 With the exception that words are used as the delimiter instead of big‐
2252 words, this command shall be equivalent to the W command.
2253 Move to Beginning of Bigword
2255 Synopsis:
2256 [count] W
2258 If the edit buffer is empty, it shall be an error. If there are less
2260 than count bigwords between the cursor and the end of the edit buffer,
2261 count shall be adjusted to move the cursor to the last bigword in the
2262 edit buffer.
2263 If used as a motion command:
2265 1. If the associated command is c, count is 1, and the cursor is on a
2267 <blank>, the region of text shall be the current character and no
2268 further action shall be taken.
2269 2. If there are less than count bigwords between the cursor and the
2271 end of the edit buffer, then the command shall succeed, and the
2272 region of text shall include the last character of the edit buffer.
2273 3. If there are <blank> characters or an end-of-line that precede the
2275 countth bigword, and the associated command is c, the region of
2276 text shall be up to and including the last character before the
2277 preceding <blank> characters or end-of-line.
2278 4. If there are <blank> characters or an end-of-line that precede the
2280 bigword, and the associated command is d or y, the region of text
2281 shall be up to and including the last <blank> before the start of
2282 the bigword or end-of-line.
2283 5. Any text copied to a buffer shall be in character mode.
2285 If not used as a motion command:
2287 1. If the cursor is on the last character of the edit buffer, it shall
2289 be an error.
2290 Current line: Set to the line containing the current column.
2292 Current column: Set to the last column in which any part of the first
2294 character of the countth next bigword is displayed.
2295 Delete Character at Cursor
2297 Synopsis:
2298 [buffer][count] x
2300 Delete the count characters at and after the current character into
2302 buffer, if specified, and into the unnamed buffer.
2303 If the line is empty, it shall be an error. If there are less than
2305 count non-<newline> characters at and after the cursor on the current
2306 line, count shall be adjusted to the number of non-<newline> characters
2307 at and after the cursor.
2308 Current line: Unchanged.
2310 Current column: If the line is empty, set to column position 1. Other‐
2312 wise, if there were count or less non-<newline> characters at and after
2313 the cursor on the current line, set to the last column that displays
2314 any part of the last non-<newline> of the line. Otherwise, unchanged.
2315 Delete Character Before Cursor
2317 Synopsis:
2318 [buffer][count] X
2320 Delete the count characters before the current character into buffer,
2322 if specified, and into the unnamed buffer.
2323 If there are no characters before the current character on the current
2325 line, it shall be an error. If there are less than count previous char‐
2326 acters on the current line, count shall be adjusted to the number of
2327 previous characters on the line.
2328 Current line: Unchanged.
2330 Current column: Set to (current column - the width of the deleted char‐
2332 acters).
2333 Yank
2335 Synopsis:
2336 [buffer][count] y motion
2338 Copy (yank) the region of text into buffer, if specified, and into the
2340 unnamed buffer.
2341 If the motion command is the y command repeated:
2343 1. The buffer shall be in line mode.
2345 2. If there are less than count -1 lines after the current line in the
2347 edit buffer, it shall be an error.
2348 3. The text region shall be from the current line up to and including
2350 the next count -1 lines.
2351 Otherwise, the buffer text mode and text region shall be as specified
2353 by the motion command.
2354 Current line: If the motion was from the current cursor position toward
2356 the end of the edit buffer, unchanged. Otherwise, set to the first line
2357 in the edit buffer that is part of the text region specified by the
2358 motion command.
2359 Current column:
2361 1. If the motion was from the current cursor position toward the end
2363 of the edit buffer, unchanged.
2364 2. Otherwise, if the current line is empty, set to column position 1.
2366 3. Otherwise, set to the last column that displays any part of the
2368 first character in the file that is part of the text region speci‐
2369 fied by the motion command.
2370 Yank Current Line
2372 Synopsis:
2373 [buffer][count] Y
2375 This command shall be equivalent to the vi command:
2377 [buffer][count] y_
2380 Redraw Window
2382 If in open mode, the z command shall have the Synopsis:
2383 Synopsis:
2385 [count] z
2387 If count is not specified, it shall default to the window edit option
2389 -1. The z command shall be equivalent to the ex z command, with a type
2390 character of = and a count of count -2, except that the current line
2391 and current column shall be set as follows, and the window edit option
2392 shall not be affected. If the calculation for the count argument would
2393 result in a negative number, the count argument to the ex z command
2394 shall be zero. A blank line shall be written after the last line is
2395 written.
2396 Current line: Unchanged.
2398 Current column: Unchanged.
2400 If not in open mode, the z command shall have the following Synopsis:
2402 Synopsis:
2404 [line] z [count] character
2406 If line is not specified, it shall default to the current line. If line
2408 is specified, but is greater than the number of lines in the edit buf‐
2409 fer, it shall default to the number of lines in the edit buffer.
2410 If count is specified, the value of the window edit option shall be set
2412 to count (as described in the ex window command), and the screen shall
2413 be redrawn.
2414 line shall be placed as specified by the following characters:
2416 <newline>, <carriage-return>
2418 Place the beginning of the line on the first line of the display.
2419 . Place the beginning of the line in the center of the display. The
2421 middle line of the display shall be calculated as described for
2422 the M command.
2423 - Place an unspecified portion of the line on the last line of the
2425 display.
2426 + If line was specified, equivalent to the <newline> case. If line
2428 was not specified, display a screen where the first line of the
2429 display shall be (current last line) +1. If there are no lines
2430 after the last line in the display, it shall be an error.
2431 ^ If line was specified, display a screen where the last line of
2433 the display shall contain an unspecified portion of the first
2434 line of a display that had an unspecified portion of the speci‐
2435 fied line on the last line of the display. If this calculation
2436 results in a line before the beginning of the edit buffer, dis‐
2437 play the first screen of the edit buffer.
2438 Otherwise, display a screen where the last line of the display
2440 shall contain an unspecified portion of (current first line -1).
2441 If this calculation results in a line before the beginning of the
2442 edit buffer, it shall be an error.
2443 Current line: If line and the '^' character were specified:
2445 1. If the first screen was displayed as a result of the command
2447 attempting to display lines before the beginning of the edit buf‐
2448 fer: if the first screen was already displayed, unchanged; other‐
2449 wise, set to (current first line -1).
2450 2. Otherwise, set to the last line of the display.
2452 If line and the '+' character were specified, set to the first line of
2454 the display.
2455 Otherwise, if line was specified, set to line.
2457 Otherwise, unchanged.
2459 Current column: Set to non-<blank>.
2461 Exit
2463 Synopsis:
2464 ZZ
2466 This command shall be equivalent to the ex xit command with no
2468 addresses, trailing !, or filename (see the ex xit command).
2469 Input Mode Commands in vi
2471 In text input mode, the current line shall consist of zero or more of
2472 the following categories, plus the terminating <newline>:
2473 1. Characters preceding the text input entry point
2475 Characters in this category shall not be modified during text input
2477 mode.
2478 2. autoindent characters
2480 autoindent characters shall be automatically inserted into each
2482 line that is created in text input mode, either as a result of
2483 entering a <newline> or <carriage-return> while in text input mode,
2484 or as an effect of the command itself; for example, O or o (see the
2485 ex autoindent command), as if entered by the user.
2486 It shall be possible to erase autoindent characters with the <con‐
2488 trol>‐D command; it is unspecified whether they can be erased by
2489 <control>‐H, <control>‐U, and <control>‐W characters. Erasing any
2490 autoindent character turns the glyph into erase-columns and deletes
2491 the character from the edit buffer, but does not change its repre‐
2492 sentation on the screen.
2493 3. Text input characters
2495 Text input characters are the characters entered by the user. Eras‐
2497 ing any text input character turns the glyph into erase-columns and
2498 deletes the character from the edit buffer, but does not change its
2499 representation on the screen.
2500 Each text input character entered by the user (that does not have a
2502 special meaning) shall be treated as follows:
2503 a. The text input character shall be appended to the last charac‐
2505 ter in the edit buffer from the first, second, or third cate‐
2506 gories.
2507 b. If there are no erase-columns on the screen, the text input
2509 command was the R command, and characters in the fifth category
2510 from the original line follow the cursor, the next such charac‐
2511 ter shall be deleted from the edit buffer. If the slowopen edit
2512 option is not set, the corresponding glyph on the screen shall
2513 become erase-columns.
2514 c. If there are erase-columns on the screen, as many columns as
2516 they occupy, or as are necessary, shall be overwritten to dis‐
2517 play the text input character. (If only part of a multi-column
2518 glyph is overwritten, the remainder shall be left on the
2519 screen, and continue to be treated as erase-columns; it is
2520 unspecified whether the remainder of the glyph is modified in
2521 any way.)
2522 d. If additional display line columns are needed to display the
2524 text input character:
2525 i. If the slowopen edit option is set, the text input charac‐
2527 ters shall be displayed on subsequent display line col‐
2528 umns, overwriting any characters displayed in those col‐
2529 umns.
2530 ii. Otherwise, any characters currently displayed on or after
2532 the column on the display line where the text input char‐
2533 acter is to be displayed shall be pushed ahead the number
2534 of display line columns necessary to display the rest of
2535 the text input character.
2536 4. Erase-columns
2538 Erase-columns are not logically part of the edit buffer, appearing
2540 only on the screen, and may be overwritten on the screen by subse‐
2541 quent text input characters. When text input mode ends, all erase-
2542 columns shall no longer appear on the screen.
2543 Erase-columns are initially the region of text specified by the c
2545 command (see Change); however, erasing autoindent or text input
2546 characters causes the glyphs of the erased characters to be treated
2547 as erase-columns.
2548 5. Characters following the text region for the c command, or the text
2550 input entry point for all other commands
2551 Characters in this category shall not be modified during text input
2553 mode, except as specified in category 3.b. for the R text input
2554 command, or as <blank> characters deleted when a <newline> or <car‐
2555 riage-return> is entered.
2556 It is unspecified whether it is an error to attempt to erase past the
2558 beginning of a line that was created by the entry of a <newline> or
2559 <carriage-return> during text input mode. If it is not an error, the
2560 editor shall behave as if the erasing character was entered immediately
2561 after the last text input character entered on the previous line, and
2562 all of the non-<newline> characters on the current line shall be
2563 treated as erase-columns.
2564 When text input mode is entered, or after a text input mode character
2566 is entered (except as specified for the special characters below), the
2567 cursor shall be positioned as follows:
2568 1. On the first column that displays any part of the first erase-col‐
2570 umn, if one exists
2571 2. Otherwise, if the slowopen edit option is set, on the first display
2573 line column after the last character in the first, second, or third
2574 categories, if one exists
2575 3. Otherwise, the first column that displays any part of the first
2577 character in the fifth category, if one exists
2578 4. Otherwise, the display line column after the last character in the
2580 first, second, or third categories, if one exists
2581 5. Otherwise, on column position 1
2583 The characters that are updated on the screen during text input mode
2585 are unspecified, other than that the last text input character shall
2586 always be updated, and, if the slowopen edit option is not set, the
2587 current cursor character shall always be updated.
2588 The following specifications are for command characters entered during
2590 text input mode.
2591 NUL
2593 Synopsis:
2594 NUL
2596 If the first character of the text input is a NUL, the most recently
2598 input text shall be input as if entered by the user, and then text
2599 input mode shall be exited. The text shall be input literally; that is,
2600 characters are neither macro or abbreviation expanded, nor are any
2601 characters interpreted in any special manner. It is unspecified whether
2602 implementations shall support more than 256 bytes of remembered input
2603 text.
2604 <control>-D
2606 Synopsis:
2607 <control>-D
2609 The <control>‐D character shall have no special meaning when in text
2611 input mode for a line-oriented command (see Command Descriptions in
2612 vi).
2613 This command need not be supported on block-mode terminals.
2615 If the cursor does not follow an autoindent character, or an autoindent
2617 character and a '0' or '^' character:
2618 1. If the cursor is in column position 1, the <control>‐D character
2620 shall be discarded and no further action taken.
2621 2. Otherwise, the <control>‐D character shall have no special meaning.
2623 If the last input character was a '0', the cursor shall be moved to
2625 column position 1.
2626 Otherwise, if the last input character was a '^', the cursor shall be
2628 moved to column position 1. In addition, the autoindent level for the
2629 next input line shall be derived from the same line from which the
2630 autoindent level for the current input line was derived.
2631 Otherwise, the cursor shall be moved back to the column after the pre‐
2633 vious shiftwidth (see the ex shiftwidth command) boundary.
2634 All of the glyphs on columns between the starting cursor position and
2636 (inclusively) the ending cursor position shall become erase-columns as
2637 described in Input Mode Commands in vi.
2638 Current line: Unchanged.
2640 Current column: Set to 1 if the <control>‐D was preceded by a '^' or
2642 '0'; otherwise, set to (column -1) -((column -2) % shiftwidth).
2643 <control>-H
2645 Synopsis:
2646 <control>-H
2648 If in text input mode for a line-oriented command, and there are no
2650 characters to erase, text input mode shall be terminated, no further
2651 action shall be done for this command, and the current line and column
2652 shall be unchanged.
2653 If there are characters other than autoindent characters that have been
2655 input on the current line before the cursor, the cursor shall move back
2656 one character.
2657 Otherwise, if there are autoindent characters on the current line
2659 before the cursor, it is implementation-defined whether the <control>‐H
2660 command is an error or if the cursor moves back one autoindent charac‐
2661 ter.
2662 Otherwise, if the cursor is in column position 1 and there are previous
2664 lines that have been input, it is implementation-defined whether the
2665 <control>‐H command is an error or if it is equivalent to entering
2666 <control>‐H after the last input character on the previous input line.
2667 Otherwise, it shall be an error.
2669 All of the glyphs on columns between the starting cursor position and
2671 (inclusively) the ending cursor position shall become erase-columns as
2672 described in Input Mode Commands in vi.
2673 The current erase character (see stty) shall cause an equivalent action
2675 to the <control>‐H command, unless the previously inserted character
2676 was a <backslash>, in which case it shall be as if the literal current
2677 erase character had been inserted instead of the <backslash>.
2678 Current line: Unchanged, unless previously input lines are erased, in
2680 which case it shall be set to line -1.
2681 Current column: Set to the first column that displays any portion of
2683 the character backed up over.
2684 <newline>
2686 Synopsis:
2687 <newline>
2689 <carriage-return>
2690 <control>-J
2691 <control>-M
2692 If input was part of a line-oriented command, text input mode shall be
2694 terminated and the command shall continue execution with the input pro‐
2695 vided.
2696 Otherwise, terminate the current line. If there are no characters other
2698 than autoindent characters on the line, all characters on the line
2699 shall be discarded. Otherwise, it is unspecified whether the autoin‐
2700 dent characters in the line are modified by entering these characters.
2701 Continue text input mode on a new line appended after the current line.
2703 If the slowopen edit option is set, the lines on the screen below the
2704 current line shall not be pushed down, but the first of them shall be
2705 cleared and shall appear to be overwritten. Otherwise, the lines of the
2706 screen below the current line shall be pushed down.
2707 If the autoindent edit option is set, an appropriate number of autoin‐
2709 dent characters shall be added as a prefix to the line as described by
2710 the ex autoindent edit option.
2711 All columns after the cursor that are erase-columns (as described in
2713 Input Mode Commands in vi) shall be discarded.
2714 If the autoindent edit option is set, all <blank> characters immedi‐
2716 ately following the cursor shall be discarded.
2717 All remaining characters after the cursor shall be transferred to the
2719 new line, positioned after any autoindent characters.
2720 Current line: Set to current line +1.
2722 Current column: Set to the first column that displays any portion of
2724 the first character after the autoindent characters on the new line, if
2725 any, or the first column position after the last autoindent character,
2726 if any, or column position 1.
2727 <control>-T
2729 Synopsis:
2730 <control>-T
2732 The <control>‐T character shall have no special meaning when in text
2734 input mode for a line-oriented command (see Command Descriptions in
2735 vi).
2736 This command need not be supported on block-mode terminals.
2738 Behave as if the user entered the minimum number of <blank> characters
2740 necessary to move the cursor forward to the column position after the
2741 next shiftwidth (see the ex shiftwidth command) boundary.
2742 Current line: Unchanged.
2744 Current column: Set to column + shiftwidth - ((column -1) %
2746 shiftwidth).
2747 <control>-U
2749 Synopsis:
2750 <control>-U
2752 If there are characters other than autoindent characters that have been
2754 input on the current line before the cursor, the cursor shall move to
2755 the first character input after the autoindent characters.
2756 Otherwise, if there are autoindent characters on the current line
2758 before the cursor, it is implementation-defined whether the <control>‐U
2759 command is an error or if the cursor moves to the first column position
2760 on the line.
2761 Otherwise, if the cursor is in column position 1 and there are previous
2763 lines that have been input, it is implementation-defined whether the
2764 <control>‐U command is an error or if it is equivalent to entering
2765 <control>‐U after the last input character on the previous input line.
2766 Otherwise, it shall be an error.
2768 All of the glyphs on columns between the starting cursor position and
2770 (inclusively) the ending cursor position shall become erase-columns as
2771 described in Input Mode Commands in vi.
2772 The current kill character (see stty) shall cause an equivalent action
2774 to the <control>‐U command, unless the previously inserted character
2775 was a <backslash>, in which case it shall be as if the literal current
2776 kill character had been inserted instead of the <backslash>.
2777 Current line: Unchanged, unless previously input lines are erased, in
2779 which case it shall be set to line -1.
2780 Current column: Set to the first column that displays any portion of
2782 the last character backed up over.
2783 <control>-V
2785 Synopsis:
2786 <control>-V
2788 <control>-Q
2789 Allow the entry of any subsequent character, other than <control>‐J or
2791 the <newline>, as a literal character, removing any special meaning
2792 that it may have to the editor in text input mode. If a <control>‐V or
2793 <control>‐Q is entered before a <control>‐J or <newline>, the <con‐
2794 trol>‐V or <control>‐Q character shall be discarded, and the <con‐
2795 trol>‐J or <newline> shall behave as described in the <newline> command
2796 character during input mode.
2797 For purposes of the display only, the editor shall behave as if a '^'
2799 character was entered, and the cursor shall be positioned as if over‐
2800 writing the '^' character. When a subsequent character is entered, the
2801 editor shall behave as if that character was entered instead of the
2802 original <control>‐V or <control>‐Q character.
2803 Current line: Unchanged.
2805 Current column: Unchanged.
2807 <control>-W
2809 Synopsis:
2810 <control>-W
2812 If there are characters other than autoindent characters that have been
2814 input on the current line before the cursor, the cursor shall move back
2815 over the last word preceding the cursor (including any <blank> charac‐
2816 ters between the end of the last word and the current cursor); the cur‐
2817 sor shall not move to before the first character after the end of any
2818 autoindent characters.
2819 Otherwise, if there are autoindent characters on the current line
2821 before the cursor, it is implementation-defined whether the <control>‐W
2822 command is an error or if the cursor moves to the first column position
2823 on the line.
2824 Otherwise, if the cursor is in column position 1 and there are previous
2826 lines that have been input, it is implementation-defined whether the
2827 <control>‐W command is an error or if it is equivalent to entering
2828 <control>‐W after the last input character on the previous input line.
2829 Otherwise, it shall be an error.
2831 All of the glyphs on columns between the starting cursor position and
2833 (inclusively) the ending cursor position shall become erase-columns as
2834 described in Input Mode Commands in vi.
2835 Current line: Unchanged, unless previously input lines are erased, in
2837 which case it shall be set to line -1.
2838 Current column: Set to the first column that displays any portion of
2840 the last character backed up over.
2841 <ESC>
2843 Synopsis:
2844 <ESC>
2846 If input was part of a line-oriented command:
2848 1. If interrupt was entered, text input mode shall be terminated and
2850 the editor shall return to command mode. The terminal shall be
2851 alerted.
2852 2. If <ESC> was entered, text input mode shall be terminated and the
2854 command shall continue execution with the input provided.
2855 Otherwise, terminate text input mode and return to command mode.
2857 Any autoindent characters entered on newly created lines that have no
2859 other non-<newline> characters shall be deleted.
2860 Any leading autoindent and <blank> characters on newly created lines
2862 shall be rewritten to be the minimum number of <blank> characters pos‐
2863 sible.
2864 The screen shall be redisplayed as necessary to match the contents of
2866 the edit buffer.
2867 Current line: Unchanged.
2869 Current column:
2871 1. If there are text input characters on the current line, the column
2873 shall be set to the last column where any portion of the last text
2874 input character is displayed.
2875 2. Otherwise, if a character is displayed in the current column,
2877 unchanged.
2878 3. Otherwise, set to column position 1.
2880
2882 The following exit values shall be returned:
2883 0 Successful completion.
2885 >0 An error occurred.
2887
2889 When any error is encountered and the standard input is not a terminal
2890 device file, vi shall not write the file or return to command or text
2891 input mode, and shall terminate with a non-zero exit status.
2892 Otherwise, when an unrecoverable error is encountered it shall be
2894 equivalent to a SIGHUP asynchronous event.
2895 Otherwise, when an error is encountered, the editor shall behave as
2897 specified in Command Descriptions in vi.
2898 The following sections are informative.
2900
2902 None.
2903
2905 None.
2906
2908 See the RATIONALE for ex for more information on vi. Major portions of
2909 the vi utility specification point to ex to avoid inadvertent diver‐
2910 gence. While ex and vi have historically been implemented as a single
2911 utility, this is not required by POSIX.1‐2008.
2912 It is recognized that portions of vi would be difficult, if not impos‐
2914 sible, to implement satisfactorily on a block-mode terminal, or a ter‐
2915 minal without any form of cursor addressing, thus it is not a mandatory
2916 requirement that such features should work on all terminals. It is the
2917 intention, however, that a vi implementation should provide the full
2918 set of capabilities on all terminals capable of supporting them.
2919 Historically, vi exited immediately if the standard input was not a
2921 terminal. POSIX.1‐2008 permits, but does not require, this behavior. An
2922 end-of-file condition is not equivalent to an end-of-file character. A
2923 common end-of-file character, <control>‐D, is historically a vi com‐
2924 mand.
2925 The text in the STDOUT section reflects the usage of the verb display
2927 in this section; some implementations of vi use standard output to
2928 write to the terminal, but POSIX.1‐2008 does not require that to be the
2929 case.
2930 Historically, implementations reverted to open mode if the terminal was
2932 incapable of supporting full visual mode. POSIX.1‐2008 requires this
2933 behavior. Historically, the open mode of vi behaved roughly equiva‐
2934 lently to the visual mode, with the exception that only a single line
2935 from the edit buffer (one ``buffer line'') was kept current at any
2936 time. This line was normally displayed on the next-to-last line of a
2937 terminal with cursor addressing (and the last line performed its normal
2938 visual functions for line-oriented commands and messages). In addition,
2939 some few commands behaved differently in open mode than in visual mode.
2940 POSIX.1‐2008 requires conformance to historical practice.
2941 Historically, ex and vi implementations have expected text to proceed
2943 in the usual European/Latin order of left to right, top to bottom.
2944 There is no requirement in POSIX.1‐2008 that this be the case. The
2945 specification was deliberately written using words like ``before'',
2946 ``after'', ``first'', and ``last'' in order to permit implementations
2947 to support the natural text order of the language.
2948 Historically, lines past the end of the edit buffer were marked with
2950 single <tilde> ('~') characters; that is, if the one-based display was
2951 20 lines in length, and the last line of the file was on line one, then
2952 lines 2-20 would contain only a single '~' character.
2953 Historically, the vi editor attempted to display only complete lines at
2955 the bottom of the screen (it did display partial lines at the top of
2956 the screen). If a line was too long to fit in its entirety at the bot‐
2957 tom of the screen, the screen lines where the line would have been dis‐
2958 played were displayed as single '@' characters, instead of displaying
2959 part of the line. POSIX.1‐2008 permits, but does not require, this
2960 behavior. Implementations are encouraged to attempt always to display a
2961 complete line at the bottom of the screen when doing scrolling or
2962 screen positioning by buffer lines.
2963 Historically, lines marked with '@' were also used to minimize output
2965 to dumb terminals over slow lines; that is, changes local to the cursor
2966 were updated, but changes to lines on the screen that were not close to
2967 the cursor were simply marked with an '@' sign instead of being updated
2968 to match the current text. POSIX.1‐2008 permits, but does not require
2969 this feature because it is used ever less frequently as terminals
2970 become smarter and connections are faster.
2971 Initialization in ex and vi
2973 Historically, vi always had a line in the edit buffer, even if the edit
2974 buffer was ``empty''. For example:
2975 1. The ex command = executed from visual mode wrote ``1'' when the
2977 buffer was empty.
2978 2. Writes from visual mode of an empty edit buffer wrote files of a
2980 single character (a <newline>), while writes from ex mode of an
2981 empty edit buffer wrote empty files.
2982 3. Put and read commands into an empty edit buffer left an empty line
2984 at the top of the edit buffer.
2985 For consistency, POSIX.1‐2008 does not permit any of these behaviors.
2987 Historically, vi did not always return the terminal to its original
2989 modes; for example, ICRNL was modified if it was not originally set.
2990 POSIX.1‐2008 does not permit this behavior.
2991 Command Descriptions in vi
2993 Motion commands are among the most complicated aspects of vi to
2994 describe. With some exceptions, the text region and buffer type effect
2995 of a motion command on a vi command are described on a case-by-case
2996 basis. The descriptions of text regions in POSIX.1‐2008 are not
2997 intended to imply direction; that is, an inclusive region from line n
2998 to line n+5 is identical to a region from line n+5 to line n. This is
2999 of more than academic interest—movements to marks can be in either
3000 direction, and, if the wrapscan option is set, so can movements to
3001 search points. Historically, lines are always stored into buffers in
3002 text order; that is, from the start of the edit buffer to the end.
3003 POSIX.1‐2008 requires conformance to historical practice.
3004 Historically, command counts were applied to any associated motion, and
3006 were multiplicative to any supplied motion count. For example, 2cw is
3007 the same as c2w, and 2c3w is the same as c6w. POSIX.1‐2008 requires
3008 this behavior. Historically, vi commands that used bigwords, words,
3009 paragraphs, and sentences as objects treated groups of empty lines, or
3010 lines that contained only <blank> characters, inconsistently. Some com‐
3011 mands treated them as a single entity, while others treated each line
3012 separately. For example, the w, W, and B commands treated groups of
3013 empty lines as individual words; that is, the command would move the
3014 cursor to each new empty line. The e and E commands treated groups of
3015 empty lines as a single word; that is, the first use would move past
3016 the group of lines. The b command would just beep at the user, or if
3017 done from the start of the line as a motion command, fail in unexpected
3018 ways. If the lines contained only (or ended with) <blank> characters,
3019 the w and W commands would just beep at the user, the E and e commands
3020 would treat the group as a single word, and the B and b commands would
3021 treat the lines as individual words. For consistency and simplicity of
3022 specification, POSIX.1‐2008 requires that all vi commands treat groups
3023 of empty or blank lines as a single entity, and that movement through
3024 lines ending with <blank> characters be consistent with other move‐
3025 ments.
3026 Historically, vi documentation indicated that any number of double-
3028 quotes were skipped after punctuation marks at sentence boundaries;
3029 however, implementations only skipped single-quotes. POSIX.1‐2008
3030 requires both to be skipped.
3031 Historically, the first and last characters in the edit buffer were
3033 word boundaries. This historical practice is required by POSIX.1‐2008.
3034 Historically, vi attempted to update the minimum number of columns on
3036 the screen possible, which could lead to misleading information being
3037 displayed. POSIX.1‐2008 makes no requirements other than that the cur‐
3038 rent character being entered is displayed correctly, leaving all other
3039 decisions in this area up to the implementation.
3040 Historically, lines were arbitrarily folded between columns of any
3042 characters that required multiple column positions on the screen, with
3043 the exception of tabs, which terminated at the right-hand margin.
3044 POSIX.1‐2008 permits the former and requires the latter. Implementa‐
3045 tions that do not arbitrarily break lines between columns of characters
3046 that occupy multiple column positions should not permit the cursor to
3047 rest on a column that does not contain any part of a character.
3048 The historical vi had a problem in that all movements were by buffer
3050 lines, not by display or screen lines. This is often the right thing to
3051 do; for example, single line movements, such as j or k, should work on
3052 buffer lines. Commands like dj, or j., where . is a change command,
3053 only make sense for buffer lines. It is not, however, the right thing
3054 to do for screen motion or scrolling commands like <control>‐D, <con‐
3055 trol>‐F, and H. If the window is fairly small, using buffer lines in
3056 these cases can result in completely random motion; for example, 1<con‐
3057 trol>‐D can result in a completely changed screen, without any overlap.
3058 This is clearly not what the user wanted. The problem is even worse in
3059 the case of the H, L, and M commands—as they position the cursor at the
3060 first non-<blank> of the line, they may all refer to the same location
3061 in large lines, and will result in no movement at all.
3062 In addition, if the line is larger than the screen, using buffer lines
3064 can make it impossible to display parts of the line—there are not any
3065 commands that do not display the beginning of the line in historical
3066 vi, and if both the beginning and end of the line cannot be on the
3067 screen at the same time, the user suffers. Finally, the page and half-
3068 page scrolling commands historically moved to the first non-<blank> in
3069 the new line. If the line is approximately the same size as the screen,
3070 this is inadequate because the cursor before and after a <control>‐D
3071 command will refer to the same location on the screen.
3072 Implementations of ex and vi exist that do not have these problems
3074 because the relevant commands (<control>‐B, <control>‐D, <control>‐F,
3075 <control>‐U, <control>‐Y, <control>‐E, H, L, and M) operate on display
3076 (screen) lines, not (edit) buffer lines.
3077 POSIX.1‐2008 does not permit this behavior by default because the stan‐
3079 dard developers believed that users would find it too confusing. How‐
3080 ever, historical practice has been relaxed. For example, ex and vi his‐
3081 torically attempted, albeit sometimes unsuccessfully, to never put part
3082 of a line on the last lines of a screen; for example, if a line would
3083 not fit in its entirety, no part of the line was displayed, and the
3084 screen lines corresponding to the line contained single '@' characters.
3085 This behavior is permitted, but not required by POSIX.1‐2008, so that
3086 it is possible for implementations to support long lines in small
3087 screens more reasonably without changing the commands to be oriented to
3088 the display (instead of oriented to the buffer). POSIX.1‐2008 also per‐
3089 mits implementations to refuse to edit any edit buffer containing a
3090 line that will not fit on the screen in its entirety.
3091 The display area (for example, the value of the window edit option) has
3093 historically been ``grown'', or expanded, to display new text when
3094 local movements are done in displays where the number of lines dis‐
3095 played is less than the maximum possible. Expansion has historically
3096 been the first choice, when the target line is less than the maximum
3097 possible expansion value away. Scrolling has historically been the next
3098 choice, done when the target line is less than half a display away, and
3099 otherwise, the screen was redrawn. There were exceptions, however, in
3100 that ex commands generally always caused the screen to be redrawn.
3101 POSIX.1‐2008 does not specify a standard behavior because there may be
3102 external issues, such as connection speed, the number of characters
3103 necessary to redraw as opposed to scroll, or terminal capabilities that
3104 implementations will have to accommodate.
3105 The current line in POSIX.1‐2008 maps one-to-one to a buffer line in
3107 the file. The current column does not. There are two different column
3108 values that are described by POSIX.1‐2008. The first is the current
3109 column value as set by many of the vi commands. This value is remem‐
3110 bered for the lifetime of the editor. The second column value is the
3111 actual position on the screen where the cursor rests. The two are not
3112 always the same. For example, when the cursor is backed by a multi-col‐
3113 umn character, the actual cursor position on the screen has histori‐
3114 cally been the last column of the character in command mode, and the
3115 first column of the character in input mode.
3116 Commands that set the current line, but that do not set the current
3118 cursor value (for example, j and k) attempt to get as close as possible
3119 to the remembered column position, so that the cursor tends to restrict
3120 itself to a vertical column as the user moves around in the edit buf‐
3121 fer. POSIX.1‐2008 requires conformance to historical practice, requir‐
3122 ing that the display location of the cursor on the display line be
3123 adjusted from the current column value as necessary to support this
3124 historical behavior.
3125 Historically, only a single line (and for some terminals, a single line
3127 minus 1 column) of characters could be entered by the user for the
3128 line-oriented commands; that is, :, !, /, or ?. POSIX.1‐2008 permits,
3129 but does not require, this limitation.
3130 Historically, ``soft'' errors in vi caused the terminal to be alerted,
3132 but no error message was displayed. As a general rule, no error mes‐
3133 sage was displayed for errors in command execution in vi, when the
3134 error resulted from the user attempting an invalid or impossible
3135 action, or when a searched-for object was not found. Examples of soft
3136 errors included h at the left margin, <control>‐B or [[ at the begin‐
3137 ning of the file, 2G at the end of the file, and so on. In addition,
3138 errors such as %, ]], }, ), N, n, f, F, t, and T failing to find the
3139 searched-for object were soft as well. Less consistently, / and ? dis‐
3140 played an error message if the pattern was not found, /, ?, N, and n
3141 displayed an error message if no previous regular expression had been
3142 specified, and ; did not display an error message if no previous f, F,
3143 t, or T command had occurred. Also, behavior in this area might reason‐
3144 ably be based on a runtime evaluation of the speed of a network connec‐
3145 tion. Finally, some implementations have provided error messages for
3146 soft errors in order to assist naive users, based on the value of a
3147 verbose edit option. POSIX.1‐2008 does not list specific errors for
3148 which an error message shall be displayed. Implementations should con‐
3149 form to historical practice in the absence of any strong reason to
3150 diverge.
3151 Page Backwards
3153 The <control>‐B and <control>‐F commands historically considered it an
3154 error to attempt to page past the beginning or end of the file, whereas
3155 the <control>‐D and <control>‐U commands simply moved to the beginning
3156 or end of the file. For consistency, POSIX.1‐2008 requires the latter
3157 behavior for all four commands. All four commands still consider it an
3158 error if the current line is at the beginning (<control>‐B, <con‐
3159 trol>‐U) or end (<control>‐F, <control>‐D) of the file. Historically,
3160 the <control>‐B and <control>‐F commands skip two lines in order to
3161 include overlapping lines when a single command is entered. This makes
3162 less sense in the presence of a count, as there will be, by definition,
3163 no overlapping lines. The actual calculation used by historical imple‐
3164 mentations of the vi editor for <control>‐B was:
3165 ((current first line) - count x (window edit option)) +2
3168 and for <control>‐F was:
3170 ((current first line) + count x (window edit option)) -2
3173 This calculation does not work well when intermixing commands with and
3175 without counts; for example, 3<control>‐F is not equivalent to entering
3176 the <control>‐F command three times, and is not reversible by entering
3177 the <control>‐B command three times. For consistency with other vi com‐
3178 mands that take counts, POSIX.1‐2008 requires a different calculation.
3179 Scroll Forward
3181 The 4BSD and System V implementations of vi differed on the initial
3182 value used by the scroll command. 4BSD used:
3183 ((window edit option) +1) /2
3186 while System V used the value of the scroll edit option. The System V
3188 version is specified by POSIX.1‐2008 because the standard developers
3189 believed that it was more intuitive and permitted the user a method of
3190 setting the scroll value initially without also setting the number of
3191 lines that are displayed.
3192 Scroll Forward by Line
3194 Historically, the <control>‐E and <control>‐Y commands considered it an
3195 error if the last and first lines, respectively, were already on the
3196 screen. POSIX.1‐2008 requires conformance to historical practice. His‐
3197 torically, the <control>‐E and <control>‐Y commands had no effect in
3198 open mode. For simplicity and consistency of specification,
3199 POSIX.1‐2008 requires that they behave as usual, albeit with a single
3200 line screen.
3201 Clear and Redisplay
3203 The historical <control>‐L command refreshed the screen exactly as it
3204 was supposed to be currently displayed, replacing any '@' characters
3205 for lines that had been deleted but not updated on the screen with
3206 refreshed '@' characters. The intent of the <control>‐L command is to
3207 refresh when the screen has been accidentally overwritten; for example,
3208 by a write command from another user, or modem noise.
3209 Redraw Screen
3211 The historical <control>‐R command redisplayed only when necessary to
3212 update lines that had been deleted but not updated on the screen and
3213 that were flagged with '@' characters. There is no requirement that the
3214 screen be in any way refreshed if no lines of this form are currently
3215 displayed. POSIX.1‐2008 permits implementations to extend this command
3216 to refresh lines on the screen flagged with '@' characters because they
3217 are too long to be displayed in the current framework; however, the
3218 current line and column need not be modified.
3219 Search for tagstring
3221 Historically, the first non-<blank> at or after the cursor was the
3222 first character, and all subsequent characters that were word charac‐
3223 ters, up to the end of the line, were included. For example, with the
3224 cursor on the leading <space> or on the '#' character in the text
3225 "#bar@", the tag was "#bar". On the character 'b' it was "bar", and on
3226 the 'a' it was "ar". POSIX.1‐2008 requires this behavior.
3227 Replace Text with Results from Shell Command
3229 Historically, the <, >, and ! commands considered most cursor motions
3230 other than line-oriented motions an error; for example, the command
3231 >/foo<CR> succeeded, while the command >l failed, even though the text
3232 region described by the two commands might be identical. For consis‐
3233 tency, all three commands only consider entire lines and not partial
3234 lines, and the region is defined as any line that contains a character
3235 that was specified by the motion.
3236 Move to Matching Character
3238 Other matching characters have been left implementation-defined in
3239 order to allow extensions such as matching '<' and '>' for searching
3240 HTML, or #ifdef, #else, and #endif for searching C source.
3241 Repeat Substitution
3243 POSIX.1‐2008 requires that any c and g flags specified to the previous
3244 substitute command be ignored; however, the r flag may still apply, if
3245 supported by the implementation.
3246 Return to Previous (Context or Section)
3248 The [[, ]], (, ), {, and } commands are all affected by ``section
3249 boundaries'', but in some historical implementations not all of the
3250 commands recognize the same section boundaries. This is a bug, not a
3251 feature, and a unique section-boundary algorithm was not described for
3252 each command. One special case that is preserved is that the sentence
3253 command moves to the end of the last line of the edit buffer while the
3254 other commands go to the beginning, in order to preserve the tradi‐
3255 tional character cut semantics of the sentence command. Historically,
3256 vi section boundaries at the beginning and end of the edit buffer were
3257 the first non-<blank> on the first and last lines of the edit buffer if
3258 one exists; otherwise, the last character of the first and last lines
3259 of the edit buffer if one exists. To increase consistency with other
3260 section locations, this has been simplified by POSIX.1‐2008 to the
3261 first character of the first and last lines of the edit buffer, or the
3262 first and the last lines of the edit buffer if they are empty.
3263 Sentence boundaries were problematic in the historical vi. They were
3265 not only the boundaries as defined for the section and paragraph com‐
3266 mands, but they were the first non-<blank> that occurred after those
3267 boundaries, as well. Historically, the vi section commands were docu‐
3268 mented as taking an optional window size as a count preceding the com‐
3269 mand. This was not implemented in historical versions, so POSIX.1‐2008
3270 requires that the count repeat the command, for consistency with other
3271 vi commands.
3272 Repeat
3274 Historically, mapped commands other than text input commands could not
3275 be repeated using the period command. POSIX.1‐2008 requires conformance
3276 to historical practice.
3277 The restrictions on the interpretation of special characters (for exam‐
3279 ple, <control>‐H) in the repetition of text input mode commands is
3280 intended to match historical practice. For example, given the input
3281 sequence:
3282 iab<control>-H<control>-H<control>-Hdef<escape>
3285 the user should be informed of an error when the sequence is first
3287 entered, but not during a command repetition. The character <control>‐T
3288 is specifically exempted from this restriction. Historical implementa‐
3289 tions of vi ignored <control>‐T characters that were input in the orig‐
3290 inal command during command repetition. POSIX.1‐2008 prohibits this
3291 behavior.
3292 Find Regular Expression
3294 Historically, commands did not affect the line searched to or from if
3295 the motion command was a search (/, ?, N, n) and the final position was
3296 the start/end of the line. There were some special cases and vi was not
3297 consistent. POSIX.1‐2008 does not permit this behavior, for consis‐
3298 tency. Historical implementations permitted but were unable to handle
3299 searches as motion commands that wrapped (that is, due to the edit
3300 option wrapscan) to the original location. POSIX.1‐2008 requires that
3301 this behavior be treated as an error.
3302 Historically, the syntax "/RE/0" was used to force the command to cut
3304 text in line mode. POSIX.1‐2008 requires conformance to historical
3305 practice.
3306 Historically, in open mode, a z specified to a search command redis‐
3308 played the current line instead of displaying the current screen with
3309 the current line highlighted. For consistency and simplicity of speci‐
3310 fication, POSIX.1‐2008 does not permit this behavior.
3311 Historically, trailing z commands were permitted and ignored if entered
3313 as part of a search used as a motion command. For consistency and sim‐
3314 plicity of specification, POSIX.1‐2008 does not permit this behavior.
3315 Execute an ex Command
3317 Historically, vi implementations restricted the commands that could be
3318 entered on the colon command line (for example, append and change), and
3319 some other commands were known to cause them to fail catastrophically.
3320 For consistency, POSIX.1‐2008 does not permit these restrictions. When
3321 executing an ex command by entering :, it is not possible to enter a
3322 <newline> as part of the command because it is considered the end of
3323 the command. A different approach is to enter ex command mode by using
3324 the vi Q command (and later resuming visual mode with the ex vi com‐
3325 mand). In ex command mode, the single-line limitation does not exist.
3326 So, for example, the following is valid:
3327 Q
3330 s/break here/break\
3331 here/
3332 vi
3333 POSIX.1‐2008 requires that, if the ex command overwrites any part of
3335 the screen that would be erased by a refresh, vi pauses for a character
3336 from the user. Historically, this character could be any character; for
3337 example, a character input by the user before the message appeared, or
3338 even a mapped character. This is probably a bug, but implementations
3339 that have tried to be more rigorous by requiring that the user enter a
3340 specific character, or that the user enter a character after the mes‐
3341 sage was displayed, have been forced by user indignation back into his‐
3342 torical behavior. POSIX.1‐2008 requires conformance to historical prac‐
3343 tice.
3344 Shift Left (Right)
3346 Refer to the Rationale for the ! and / commands. Historically, the <
3347 and > commands sometimes moved the cursor to the first non-<blank> (for
3348 example if the command was repeated or with _ as the motion command),
3349 and sometimes left it unchanged. POSIX.1‐2008 does not permit this
3350 inconsistency, requiring instead that the cursor always move to the
3351 first non-<blank>. Historically, the < and > commands did not support
3352 buffer arguments, although some implementations allow the specification
3353 of an optional buffer. This behavior is neither required nor disallowed
3354 by POSIX.1‐2008.
3355 Execute
3357 Historically, buffers could execute other buffers, and loops, infinite
3358 and otherwise, were possible. POSIX.1‐2008 requires conformance to his‐
3359 torical practice. The *buffer syntax of ex is not required in vi,
3360 because it is not historical practice and has been used in some vi
3361 implementations to support additional scripting languages.
3362 Reverse Case
3364 Historically, the ~ command ignored any associated count, and acted
3365 only on the characters in the current line. For consistency with other
3366 vi commands, POSIX.1‐2008 requires that an associated count act on the
3367 next count characters, and that the command move to subsequent lines if
3368 warranted by count, to make it possible to modify large pieces of text
3369 in a reasonably efficient manner. There exist vi implementations that
3370 optionally require an associated motion command for the ~ command.
3371 Implementations supporting this functionality are encouraged to base it
3372 on the tildedop edit option and handle the text regions and cursor
3373 positioning identically to the yank command.
3374 Append
3376 Historically, counts specified to the A, a, I, and i commands repeated
3377 the input of the first line count times, and did not repeat the subse‐
3378 quent lines of the input text. POSIX.1‐2008 requires that the entire
3379 text input be repeated count times.
3380 Move Backward to Preceding Word
3382 Historically, vi became confused if word commands were used as motion
3383 commands in empty files. POSIX.1‐2008 requires that this be an error.
3384 Historical implementations of vi had a large number of bugs in the word
3385 movement commands, and they varied greatly in behavior in the presence
3386 of empty lines, ``words'' made up of a single character, and lines con‐
3387 taining only <blank> characters. For consistency and simplicity of
3388 specification, POSIX.1‐2008 does not permit this behavior.
3389 Change to End-of-Line
3391 Some historical implementations of the C command did not behave as
3392 described by POSIX.1‐2008 when the $ key was remapped because they were
3393 implemented by pushing the $ key onto the input queue and reprocessing
3394 it. POSIX.1‐2008 does not permit this behavior. Historically, the C, S,
3395 and s commands did not copy replaced text into the numeric buffers. For
3396 consistency and simplicity of specification, POSIX.1‐2008 requires that
3397 they behave like their respective c commands in all respects.
3398 Delete
3400 Historically, lines in open mode that were deleted were scrolled up,
3401 and an @ glyph written over the beginning of the line. In the case of
3402 terminals that are incapable of the necessary cursor motions, the edi‐
3403 tor erased the deleted line from the screen. POSIX.1‐2008 requires con‐
3404 formance to historical practice; that is, if the terminal cannot dis‐
3405 play the '@' character, the line cannot remain on the screen.
3406 Delete to End-of-Line
3408 Some historical implementations of the D command did not behave as
3409 described by POSIX.1‐2008 when the $ key was remapped because they were
3410 implemented by pushing the $ key onto the input queue and reprocessing
3411 it. POSIX.1‐2008 does not permit this behavior.
3412 Join
3414 An historical oddity of vi is that the commands J, 1J, and 2J are all
3415 equivalent. POSIX.1‐2008 requires conformance to historical practice.
3416 The vi J command is specified in terms of the ex join command with an
3417 ex command count value. The address correction for a count that is past
3418 the end of the edit buffer is necessary for historical compatibility
3419 for both ex and vi.
3420 Mark Position
3422 Historical practice is that only lowercase letters, plus backquote and
3423 single-quote, could be used to mark a cursor position. POSIX.1‐2008
3424 requires conformance to historical practice, but encourages implementa‐
3425 tions to support other characters as marks as well.
3426 Repeat Regular Expression Find (Forward and Reverse)
3428 Historically, the N and n commands could not be used as motion compo‐
3429 nents for the c command. With the exception of the cN command, which
3430 worked if the search crossed a line boundary, the text region would be
3431 discarded, and the user would not be in text input mode. For consis‐
3432 tency and simplicity of specification, POSIX.1‐2008 does not permit
3433 this behavior.
3434 Insert Empty Line (Below and Above)
3436 Historically, counts to the O and o commands were used as the number of
3437 physical lines to open, if the terminal was dumb and the slowopen
3438 option was not set. This was intended to minimize traffic over slow
3439 connections and repainting for dumb terminals. POSIX.1‐2008 does not
3440 permit this behavior, requiring that a count to the open command behave
3441 as for other text input commands. This change to historical practice
3442 was made for consistency, and because a superset of the functionality
3443 is provided by the slowopen edit option.
3444 Put from Buffer (Following and Before)
3446 Historically, counts to the p and P commands were ignored if the buffer
3447 was a line mode buffer, but were (mostly) implemented as described in
3448 POSIX.1‐2008 if the buffer was a character mode buffer. Because imple‐
3449 mentations exist that do not have this limitation, and because pasting
3450 lines multiple times is generally useful, POSIX.1‐2008 requires that
3451 count be supported for all p and P commands.
3452 Historical implementations of vi were widely known to have major prob‐
3454 lems in the p and P commands, particularly when unusual regions of text
3455 were copied into the edit buffer. The standard developers viewed these
3456 as bugs, and they are not permitted for consistency and simplicity of
3457 specification.
3458 Historically, a P or p command (or an ex put command executed from open
3460 or visual mode) executed in an empty file, left an empty line as the
3461 first line of the file. For consistency and simplicity of specifica‐
3462 tion, POSIX.1‐2008 does not permit this behavior.
3463 Replace Character
3465 Historically, the r command did not correctly handle the erase and word
3466 erase characters as arguments, nor did it handle an associated count
3467 greater than 1 with a <carriage-return> argument, for which it replaced
3468 count characters with a single <newline>. POSIX.1‐2008 does not permit
3469 these inconsistencies.
3470 Historically, the r command permitted the <control>‐V escaping of
3472 entered characters, such as <ESC> and the <carriage-return>; however,
3473 it required two leading <control>‐V characters instead of one.
3474 POSIX.1‐2008 requires that this be changed for consistency with the
3475 other text input commands of vi.
3476 Historically, it is an error to enter the r command if there are less
3478 than count characters at or after the cursor in the line. While a rea‐
3479 sonable and unambiguous extension would be to permit the r command on
3480 empty lines, it would require that too large a count be adjusted to
3481 match the number of characters at or after the cursor for consistency,
3482 which is sufficiently different from historical practice to be avoided.
3483 POSIX.1‐2008 requires conformance to historical practice.
3484 Replace Characters
3486 Historically, if there were autoindent characters in the line on which
3487 the R command was run, and autoindent was set, the first <newline>
3488 would be properly indented and no characters would be replaced by the
3489 <newline>. Each additional <newline> would replace n characters, where
3490 n was the number of characters that were needed to indent the rest of
3491 the line to the proper indentation level. This behavior is a bug and is
3492 not permitted by POSIX.1‐2008.
3493 Undo
3495 Historical practice for cursor positioning after undoing commands was
3496 mixed. In most cases, when undoing commands that affected a single
3497 line, the cursor was moved to the start of added or changed text, or
3498 immediately after deleted text. However, if the user had moved from the
3499 line being changed, the column was either set to the first non-<blank>,
3500 returned to the origin of the command, or remained unchanged. When
3501 undoing commands that affected multiple lines or entire lines, the cur‐
3502 sor was moved to the first character in the first line restored. As an
3503 example of how inconsistent this was, a search, followed by an o text
3504 input command, followed by an undo would return the cursor to the loca‐
3505 tion where the o command was entered, but a cw command followed by an o
3506 command followed by an undo would return the cursor to the first
3507 non-<blank> of the line. POSIX.1‐2008 requires the most useful of these
3508 behaviors, and discards the least useful, in the interest of consis‐
3509 tency and simplicity of specification.
3510 Yank
3512 Historically, the yank command did not move to the end of the motion if
3513 the motion was in the forward direction. It moved to the end of the
3514 motion if the motion was in the backward direction, except for the _
3515 command, or for the G and ' commands when the end of the motion was on
3516 the current line. This was further complicated by the fact that for a
3517 number of motion commands, the yank command moved the cursor but did
3518 not update the screen; for example, a subsequent command would move the
3519 cursor from the end of the motion, even though the cursor on the screen
3520 had not reflected the cursor movement for the yank command.
3521 POSIX.1‐2008 requires that all yank commands associated with backward
3522 motions move the cursor to the end of the motion for consistency, and
3523 specifically, to make ' commands as motions consistent with search pat‐
3524 terns as motions.
3525 Yank Current Line
3527 Some historical implementations of the Y command did not behave as
3528 described by POSIX.1‐2008 when the '_' key was remapped because they
3529 were implemented by pushing the '_' key onto the input queue and repro‐
3530 cessing it. POSIX.1‐2008 does not permit this behavior.
3531 Redraw Window
3533 Historically, the z command always redrew the screen. This is permitted
3534 but not required by POSIX.1‐2008, because of the frequent use of the z
3535 command in macros such as map n nz. for screen positioning, instead of
3536 its use to change the screen size. The standard developers believed
3537 that expanding or scrolling the screen offered a better interface for
3538 users. The ability to redraw the screen is preserved if the optional
3539 new window size is specified, and in the <control>‐L and <control>‐R
3540 commands.
3541 The semantics of z^ are confusing at best. Historical practice is that
3543 the screen before the screen that ended with the specified line is dis‐
3544 played. POSIX.1‐2008 requires conformance to historical practice.
3545 Historically, the z command would not display a partial line at the top
3547 or bottom of the screen. If the partial line would normally have been
3548 displayed at the bottom of the screen, the command worked, but the par‐
3549 tial line was replaced with '@' characters. If the partial line would
3550 normally have been displayed at the top of the screen, the command
3551 would fail. For consistency and simplicity of specification,
3552 POSIX.1‐2008 does not permit this behavior.
3553 Historically, the z command with a line specification of 1 ignored the
3555 command. For consistency and simplicity of specification, POSIX.1‐2008
3556 does not permit this behavior.
3557 Historically, the z command did not set the cursor column to the first
3559 non-<blank> for the character if the first screen was to be displayed,
3560 and was already displayed. For consistency and simplicity of specifica‐
3561 tion, POSIX.1‐2008 does not permit this behavior.
3562 Input Mode Commands in vi
3564 Historical implementations of vi did not permit the user to erase more
3565 than a single line of input, or to use normal erase characters such as
3566 line erase, worderase, and erase to erase autoindent characters. As
3567 there exist implementations of vi that do not have these limitations,
3568 both behaviors are permitted, but only historical practice is required.
3569 In the case of these extensions, vi is required to pause at the autoin‐
3570 dent and previous line boundaries.
3571 Historical implementations of vi updated only the portion of the screen
3573 where the current cursor character was displayed. For example, consider
3574 the vi input keystrokes:
3575 iabcd<escape>0C<tab>
3578 Historically, the <tab> would overwrite the characters "abcd" when it
3580 was displayed. Other implementations replace only the 'a' character
3581 with the <tab>, and then push the rest of the characters ahead of the
3582 cursor. Both implementations have problems. The historical implementa‐
3583 tion is probably visually nicer for the above example; however, for the
3584 keystrokes:
3585 iabcd<ESC>0R<tab><ESC>
3588 the historical implementation results in the string "bcd" disappearing
3590 and then magically reappearing when the <ESC> character is entered.
3591 POSIX.1‐2008 requires the former behavior when overwriting erase-col‐
3592 umns—that is, overwriting characters that are no longer logically part
3593 of the edit buffer—and the latter behavior otherwise.
3594 Historical implementations of vi discarded the <control>‐D and <con‐
3596 trol>‐T characters when they were entered at places where their command
3597 functionality was not appropriate. POSIX.1‐2008 requires that the <con‐
3598 trol>‐T functionality always be available, and that <control>‐D be
3599 treated as any other key when not operating on autoindent characters.
3600 NUL
3602 Some historical implementations of vi limited the number of characters
3603 entered using the NUL input character to 256 bytes. POSIX.1‐2008 per‐
3604 mits this limitation; however, implementations are encouraged to remove
3605 this limit.
3606 <control>‐D
3608 See also Rationale for the input mode command <newline>. The hidden
3609 assumptions in the <control>‐D command (and in the vi autoindent speci‐
3610 fication in general) is that <space> characters take up a single column
3611 on the screen and that <tab> characters are comprised of an integral
3612 number of <space> characters.
3613 <newline>
3615 Implementations are permitted to rewrite autoindent characters in the
3616 line when <newline>, <carriage-return>, <control>‐D, and <control>‐T
3617 are entered, or when the shift commands are used, because historical
3618 implementations have both done so and found it necessary to do so. For
3619 example, a <control>‐D when the cursor is preceded by a single <tab>,
3620 with tabstop set to 8, and shiftwidth set to 3, will result in the
3621 <tab> being replaced by several <space> characters.
3622 <control>‐T
3624 See also the Rationale for the input mode command <newline>. Histori‐
3625 cally, <control>‐T only worked if no non-<blank> characters had yet
3626 been input in the current input line. In addition, the characters
3627 inserted by <control>‐T were treated as autoindent characters, and
3628 could not be erased using normal user erase characters. Because imple‐
3629 mentations exist that do not have these limitations, and as moving to a
3630 column boundary is generally useful, POSIX.1‐2008 requires that both
3631 limitations be removed.
3632 <control>‐V
3634 Historically, vi used ^V, regardless of the value of the literal-next
3635 character of the terminal. POSIX.1‐2008 requires conformance to his‐
3636 torical practice.
3637 The uses described for <control>‐V can also be accomplished with <con‐
3639 trol>‐Q, which is useful on terminals that use <control>‐V for the
3640 down-arrow function. However, most historical implementations use <con‐
3641 trol>‐Q for the termios START character, so the editor will generally
3642 not receive the <control>‐Q unless stty ixon mode is set to off. (In
3643 addition, some historical implementations of vi explicitly set ixon
3644 mode to on, so it was difficult for the user to set it to off.) Any of
3645 the command characters described in POSIX.1‐2008 can be made ineffec‐
3646 tive by their selection as termios control characters, using the stty
3647 utility or other methods described in the System Interfaces volume of
3648 POSIX.1‐2017.
3649 <ESC>
3651 Historically, SIGINT alerted the terminal when used to end input mode.
3652 This behavior is permitted, but not required, by POSIX.1‐2008.
3653
3655 None.
3656
3658 ed, ex, stty
3659 The Base Definitions volume of POSIX.1‐2017, Section 12.2, Utility Syn‐
3661 tax Guidelines
3662
3664 Portions of this text are reprinted and reproduced in electronic form
3665 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
3666 table Operating System Interface (POSIX), The Open Group Base Specifi‐
3667 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
3668 Electrical and Electronics Engineers, Inc and The Open Group. In the
3669 event of any discrepancy between this version and the original IEEE and
3670 The Open Group Standard, the original IEEE and The Open Group Standard
3671 is the referee document. The original Standard can be obtained online
3672 at http://www.opengroup.org/unix/online.html .
3673 Any typographical or formatting errors that appear in this page are
3675 most likely to have been introduced during the conversion of the source
3676 files to man page format. To report such errors, see https://www.ker‐
3677 nel.org/doc/man-pages/reporting_bugs.html .
3678IEEE/The Open Group 2017 VI(1P)